Bob, if you pulled your head out of your ass and thought about it like you seem to be trying to indicate you are, you'd notice that the Spartan program IS intended as the evil, oppressive, over the top militaristic side of humanity in the future war against the covenant armada.
Humanity had to design a 'master race' as you so painstakingly put it, because they were getting their asses whipped. The diversity present in the human race was getting obliterated by the multi-planetary slave army - so the UNSC made their own. Conscripts, stolen babies, genetically engineered for physical perfection and practically brainwashed in their mental programming. They only exist because of the war, they are humanity's dirty little secret.
Also, fuck you. Fuck you for your thoughtless, sarcastic dismissal of the characterisation of the Spartans. "Oh wow, the chick is a badass". Of course she is, you dolt. She's a Spartan. What's she supposed to do, pick flowers and give herself a makeover mid-battle?
Jorge looks like a big softie in comparison because he's the most stable. Being a Spartan-II he was literally bred for his role whereas the other members of Noble team have been upgraded mid-war and rightfully have some adjustment issues - not the least of which stems from the fact that the Spartan-III project was basically built on data stolen from Dr. Halsey's Spartan-II program, so the Spartan-III soldiers are even more vilified than the rest. They are the things that should not be. No longer human, but not quite a true Spartan.
Emile wants to stand out because he's a childish brat, his characterisation is that he's a tryhard, a wannabe, but you missed that because you didn't look past the skull he carved into his visor. Jun is probably the most stereotypical - the calm and collected sniper, but you completely overlooked him because you wanted to deride what you perceive as generic badassery to make your point about how Bungie promote fascism - which they don't. They do the opposite. The end of Reach is pretty clear in it's live by the sword, die by the sword mentality - but also makes it clear there was no other option. Fight or die. Fight and die.
All humanity wants to do is at least go down swinging, and Noble 6's decision in particular to stand and fight and accept that his/her sacrifice would assist in humanity's long-term survival and possibly truimph.
When the series comes full circle in Halo 3, you have Elites fighting alongside humanity - not out of a desire for token diversity but because of an alliance of necessity. Master Chief and the Arbiter are effectively the champions of their respective slave armies, who have risen above their differences and the politicking of their masters to fight a common foe. Maybe the symbolism there is intended, maybe it isn't. But since you don't care about the story of Halo and want to find symbolism to debase a series you already dislike, you could at least acknowledge that willingness to adapt and evolve as a culture, and embrace diversity, it what ultimately saves humanity. But you don't.
THAT is "the big picture".