People play alts all day if their team isn't in power. Then when one of the big ones logs on, they switch characters. I don't really know the answer. There are a bunch of cliques and buddy-groups who play this game, and you can almost tell when they all choose to join a cabal together or something similar.
I don't talk to anyone who plays this game anymore, so I play the only way I know how. But I don't know how to MAKE others play one char without OOC cheating. We just gotta deal with it. I think.
The good news is: Most of them suck ass. They only will have one real good member of their "team" and the others are all supporting them. You see this a lot with Empire and Trib.