Clan wars is an anti hopping aide..
OP,
It depends on you, and the clan to create a culture and enforce standards.
Two questions:
1- Why are you giving new players, off the streets with zero donations- good enough troops, that would make you angry when they hop?
2- Why not mandate new players must donate first / or receive basic units (archers) until they prove them selves.
And in my opinion: Clan Wars will absolutely slow down hoppers. As a player who enters a clan for war, who hops- will have to wait out a 48 hour "cool-down" before joining another clan war.
P.S. I consider checking players "Friend in Need" stats before inviting them into your clan. Its quite telling how they will act in a team environment.
Kyle
Machine Elves