Hey, I like Halo and Star Trek but neither of them have proven to be as mean as the Stargate humans, if you want the humans who would win this with the least effort I would probably have to say Macross once they got their population rebuilt a little, because they are absolutely vicious in a fight.
The first thing the Tau'ri (stargate humans) did when they found out their enemies had easily accessed teleportation devices was to use them to deliver bombs (Stargate, 1994) next when they realized their enemies wore heavy armor they switched to armor piercing rounds (Stargate SG-1 season 1 episode 2) in season 7 the Kull warriors appeared proving to be basically indestructible, it took the Stargate personnel 6 whole episodes, including the 2 parter they were introduced in, to figure out a way around them, and then they took precautions in case the Kull warriors ever modified their shielding, by creating a better version of their first weapon. While the Star Trek humans are still fighting it out with the borg and the Halo humans developed as quickly as they could but it wasn't enough and took the Covenant's head Prophet decision to replace the Elites (or carry the idiot ball for a day, however you like to look at it) with the Brutes to save the humans.
From the point in time you are suggesting, given how slow the Flood are the humans will have time to get where they need, the borg would be a minor threat and only outside the Milky Way, as the Tau'ri still have access to the Ancient weapon which destroyed the replicators, and at this point have ship mounted variants of it, which would mean that a lot of borg crews would be waking up as people on board ships that don't work right anymore. The Federation wouldn't quite know what to do with a second Earth appearing but would appreciate the help of incredibly powerful allies and the humans from Halo would still be licking their wounds from Halo 3 as they were in no condition to win a fight with anything at the end of that. 50 years later during the events of the John-117 monument they would be ready to fight some more, but the humans in Halo 3 were exhausted and could really use the break and aid provided by the Federation and the Tau'ri. The Tau'ri would make extensive use of the replication machines the Federation has as well as the information possessed by the Halo 3 humans, trade would happen and by their powers combined they would rock the galaxy, not the Flood, the Borg, the(now dead)Covenant, the Ori, or anyone would be able to beat them, although they still would have been curb-stomped by the Ori when they first engaged in ship to ship combat.
The first thing the Tau'ri (stargate humans) did when they found out their enemies had easily accessed teleportation devices was to use them to deliver bombs (Stargate, 1994) next when they realized their enemies wore heavy armor they switched to armor piercing rounds (Stargate SG-1 season 1 episode 2) in season 7 the Kull warriors appeared proving to be basically indestructible, it took the Stargate personnel 6 whole episodes, including the 2 parter they were introduced in, to figure out a way around them, and then they took precautions in case the Kull warriors ever modified their shielding, by creating a better version of their first weapon. While the Star Trek humans are still fighting it out with the borg and the Halo humans developed as quickly as they could but it wasn't enough and took the Covenant's head Prophet decision to replace the Elites (or carry the idiot ball for a day, however you like to look at it) with the Brutes to save the humans.
From the point in time you are suggesting, given how slow the Flood are the humans will have time to get where they need, the borg would be a minor threat and only outside the Milky Way, as the Tau'ri still have access to the Ancient weapon which destroyed the replicators, and at this point have ship mounted variants of it, which would mean that a lot of borg crews would be waking up as people on board ships that don't work right anymore. The Federation wouldn't quite know what to do with a second Earth appearing but would appreciate the help of incredibly powerful allies and the humans from Halo would still be licking their wounds from Halo 3 as they were in no condition to win a fight with anything at the end of that. 50 years later during the events of the John-117 monument they would be ready to fight some more, but the humans in Halo 3 were exhausted and could really use the break and aid provided by the Federation and the Tau'ri. The Tau'ri would make extensive use of the replication machines the Federation has as well as the information possessed by the Halo 3 humans, trade would happen and by their powers combined they would rock the galaxy, not the Flood, the Borg, the(now dead)Covenant, the Ori, or anyone would be able to beat them, although they still would have been curb-stomped by the Ori when they first engaged in ship to ship combat.
