I don't really care if they do that.
Wat i hate (and i think it's illegal) it's when some managers don't play because they want to tank (or other reason) but they go online and set a strong(er) team only against some other teams (maybe to help a friend to be champion),like it happened to me last 2 seasons,this is really not fair-play.
But i've won the 2 last leagues and 1 CL so......