Whats up with the alliances?

So i'm trying to host a new game, and its my first pacific map i host but it doesnt let me create it unless i use the "until full" option, thats kinda annoying but the real problem i have is with the alliance option when i use the pacific map, i dont get why when its suppose to be equal players on each alliance i see 11 people on three outta the 5 alliance that are in the game.