- Euron goes from Blackwater Bay to the ocean outside Casterly Rock in what seems like very little time at all. Getting to Casterly Rock from Blackwater Bay involves sailing around literally the entire continent [https://s-media-cache-ak0.pinimg.com/736x/ab/33/59/ab33593e3cd987a2e877c0a36da17689--map-maker-map-of-westeros.jpg], and it takes Euron past both the Tyrells and the Dornish. It's a long trip through hostile territory that he manages to accomplish through the power of the writers wanting him to.
- Rather than ambushing the Unsullied at sea, where they are at a great disadvantage (and they are literally travelling the same direction at the same time, so it's amazing that these two massive fleets didn't bump into each other just by accident) Cersei's plan is to let the Unsullied storm Casterly Rock and then attack to destroy their boats, making Cersei's strategy both improbably competent and improbably stupid at the same time.
- Jaime mentions that the Unsullied cannot hold Casterly Rock because the Lannisters had emptied the stores before leaving. A few scenes before that, Sansa pointed out the difficult logistics involved in swiftly moving massive amounts of food in and out of a castle, but Cersei and Jaime - neither of whom are strategists - are confident enough in their predictions of Daenaerys' strategy that they are willing to completely empty those considerable grain stores based on a hunch. But where did they put the food? The army can't be hauling a castle's worth of food around, and they certainly can't be doing that while blitzkrieging the Tyrells.
- Casterly Rock is the castle next to Lannisport. [http://vignette1.wikia.nocookie.net/gameofthrones/images/5/57/MapOfWesterlandsCompleteGuide.png/revision/latest?cb=20120628184950] Jaime confidently states that Casterly Rock is worthless because the gold and food are gone and the Unsullied can't hold it, but the Unsullied could literally walk next door and sack the Lannister's capital city and main trade port. How could Euron stop them when the Ironborn are useless on land? How loyal would the Lannister's bannermen be when Cersei throws their lands, people and wealth to the wolves?
- Where the hell did the raven communication service go? How come the Tyrells didn't notice ten thousand Lannisters marching up to their capital before they were literally at their doorstep? How come they couldn't send a raven warning the Unsullied that the Lannisters aren't where they thought they were? A couple of episodes ago, the ravens are smart and fast enough to move information from Dragonstone to Winterfell in between scenes. But suddenly, no-one thinks of using them.
- Where the hell did the Lannisters get ten thousand men from? They've been supplying front-line manpower in a civil war for years. They're broke. Their gold mines are exhausted and they're massively in debt. It's mentioned multiple times earlier in the series that the Tyrells have so many men that they're almost a dealmaker just by themselves. And just two seasons ago, Cersei had to arm a bunch of religious fanatics because she didn't have enough soldiers. Fan wank puts the entire strength of Cersei's army at 15,000 [https://www.reddit.com/r/asoiaf/comments/4s7onz/spoilers_everything_the_current_armies_of/] across the entire continent, optimistically. That's assuming that no Lannister bannerman switch side to Daenaerys with the Tyrells based on the prospect of being able to eat the coming winter, and assuming that there was literally zero conflict between the still-massive Tyrell army and the Lannisters. The Tyrells are supposed to be able to field fifty to a hundred thousand [http://awoiaf.westeros.org/index.php/Military_strength#The_Reach] men. They ought've walked all over Jaime Lannister's ten thousand dudes.
- What the fuck is happening with the time scale? Euron, Jaime, Jon and Grey Worm are moving all across the continent at the speed of plot, trips that should take months. I can assume that the time has passed in between scenes or episodes, but then what's happening in that time? By my reckoning, Daenaerys has been sitting on Dragonstone for half a year now, and the people of King's Landing ought to have started starving to death long before then. Sure, food isn't a problem now that you've conquered the Tyrells off-screen, Cersei. But it must have taken months of in-universe time to get to that point. Who was feeding them before then? Jon makes the massive journey from Winterfell to Blackwater Bay in between episodes, but arrives just in time for Daenaerys to hear the news of Euron's ambush, which she must have heard of before then.
- How is Daenaerys so ill-informed? She has Varys and Tyrion on her side, and she can pop up on a dragon and just fly around to get a look whenever she wants! One day of clear skies, and she ought to know exactly where the Ironborn fleet is or isn't. She has medieval air superiority, but Tyrion is worried she might get hit with an arrow? She doesn't need to get within arrow range! She just needs to see!
- Daenaerys' allies are getting knocked out one by one, but that makes no sense. Ellaria Sand gets captured and thrown in a cell, sure. But the ships were all Ironborn and there weren't even that many Dornish soldiers on them. Dorne is a huge kingdom in its own right that's famous for never having been conquered. Its inhabitants clearly hate the Lannisters enough to go along with Ellaria's insane coup at the start of season six. Why assume that they're out of the game just because Ellaria got captured? Shouldn't she have a vizier or a general or a bannerman or someone who can go "Well, that's a setback, but it's great for me because it means I'm the new prince of Dorne. Let's send our armies to go back up the Tyrells, because we all still hate the Lannisters."
- Why did Melisandre leave Dragonstone without telling anyone about the White Walkers? She wants Jon and Daenaerys to team up. She believes that Jon is an agent of prophecy. She knows that the White Walkers are coming. But instead of hanging around to mediate between Jon and Daenaerys, or even just telling anyone about the zombie apocalypse, she chooses to scarper as soon as Jon lands on the beach because...she's afraid of confrontation? It can't be fear of death; Jon swore to kill her if he ever saw her in the North again. She's not in the North, and Jon's in no position to execute her in Daenaerys' court. It seems like she left because the writers wanted to have Dany be skeptical about the army of the dead, not because of any practical reason. Why not have Dany express that skepticism in the last episode when she first met Melisandre? That way Dany doesn't come off as ignorant and Melisandre doesn't come off as absurdly incompetent. "Oh, dang, forgot to tell the Queen with the zombie-destroying dragons about the impending zombie apocalypse. Nuts. Oh well, off to Volantis."
- Daenaerys is astonishingly insistent about swearing fealty given that she just arrived in Westeros and has been counselled to seek as many allies as possible. Why demand subservience from the king of a region infamous for its stubbornness? A region in open rebellion against the dynasty she considers to be usurpers? Why not discuss an alliance first, or even any kind of diplomatic overtures whatsoever other than demanding that Jon kneel? Did she demand that the Dornish bend the knee? Did she demand Olenna bend the knee? She's sitting there trying to intimidate Jon with her list of titles and her withering gaze, but she has to know that doesn't work with Northmen. She has to know that the Stark bannermen who have declared two kings in a few years and who have every reason to hate the Targaryens would go into open revolt if Jon swore fealty to her. If she doesn't know, why don't any of her advisers? Daenaerys spent years governing in Mereen specifically so that she could learn how to govern, and a huge part of that was learning when to compromise and when to use force. But all she remembers from that is that she has a killer death stare, and when all you have is a hammer...?
- Why are the people in the streets of King's Landing cheering Euron Greyjoy when he arrives? Cersei has been a terrible ruler and they all hate her. A couple of seasons ago, they threw shit at her and called her a ****. Everyone must know that she destroyed the Sept of Baelor, which conveniently exploded on the day of her trial while she was absent and all her enemies were present. She's a mass murderer. She took the throne without a blood claim to it. She's obviously still using the Mountain because how many other eight-foot-tall knights are there? And she's not even trying to hide her relationship with Jaime! That relationship calls into question the entire foundation of her rule! Everyone already suspects that her children were all illegitimate, she's just basically confirmed it, she murdered Margaery who was beloved by the smallfolk, she blew up the kingdom's largest cathedral, she can't even feed her citizens, but the people still love her enough to cheer for a random Greyjoy on the sole basis that he arrived with some captives who they've never seen before but who are important to Cersei for personal reasons. They don't know who Euron is. They don't know who Yara is. It's doubtful they know who Ellaria Sand is. But they're cheering for him because he captured them? I mean, in the first episode they didn't show any people rioting outside the walls of the Red Keep, but I assumed that they were there. Now this one does a backflip and goes "No, no, everybody loves her, see? Because she won at something, so they're cheering now!"
- When did Cersei become so competent? She goes from a complete trainwreck of a ruler after Tywin's death to outsmarting Tyrion and Varys. How? Why does the Iron Bank trust her when she says "I'll pay back my (astronomical) debt in two weeks." Why do they see Cersei as more trustworthy or stable than Daenaerys? What is it about her murderous insanity that gives them that impression? Was it when she blew up the Sept of Baelor, or when she made an alliance with a fleet of pirates? One of the things Game of Thrones really successfully hammered in is that Cersei is dumb. She doesn't succeed because she's a master schemer like Varys or Littlefinger. She succeeds through sheer brutality and an absolute absence of any moral restraints. So when did she become omniscient? Was it before or after her spymaster swapped sides?