Well it would be pretty nice if you can have alliance's and such.
But i think in a game like this you will get 1 or 2 very big alliance's that will just dominate the players that are on there own.
I would suggest a idea though its from Black&White 1.
Back then you had clans, which people could join, but you cant fight with your entire clan against somebody else in a match ( yeah its a shame you cant fight with say your 100 man clan, vs 1 guy, but it stays fair :P )
At least like this you have a officeel clan / alliance system going on where ppl can see like stats ( how many time the entire clan won / lose & membership etc ) and perhaps a option where different alliance can challenge each other
Anyways just saying some stuff out loud:P
I Can Tell You This, I Ate A lot Of Garlic, And I Just Farted, Silent But Deadly.