But we would know, because it wouldn't show on their team profile that its the REAL one. In what i proposed, the team gets their own page with their own info and members list. I think you agree as well.
Maybe just have a forced (1) or (2) at the end of any copied name. I still don't think the player base is big enough to be worrying about the new players who don't match stealing old clans that they never knew about.
And if you're worried about the 10 people who still match and clan hop all day, then don't, because, don't.