Why only four members?

With Marvel and DC Movies trying to get as many heroes on screen as possible, this film settles with only four? Especially if they are supposed to represent different Soviet Republics and their strengths/qualities. They could have given every Republic it's own hero and come out with a super squad or made half of them villains, either way would have been awesome. I'm gonna try and come up with a hero for every country that hasn't got one in the film:

Estonia: Captain Sarcastic
Latvia: Rinkmaster
Lithuania: Triple Trouble
Belarus: The Living Tractor
Moldova: Knightterror
Georgia: Legit Jigit
Azerbaijan: Crimson Crescent.. I dunno, I guess it's harder than I thought..
You too... Immortal?  No, I just don't fear death! 