Don't see what's the problem in bringing yet another knockback to controll a wave of adds, even if it's 1 min cd.
In our tactic (kill 1 wave, cc 1 wave, kill 2 waves at the same time), it means we have 8 adds alive at the same time. We have all sort of knockbacks, but the more the better. And I like seeing huge crits flying, while i'm knockbacking them all.