The solution to this dilemma is really simple.
Either scale back the early/mid game removal for the priest (this isn't the best option, takes away much of the priest tools), or make Mind Control a "buff" and therefore able to be removed via silence.
It's the simplest fix and one I'd like to see tested.
The problem is that people are asking for fixes to something that is not broken and any solution to weaken it is for that reason poor.
Perhaps, but it's an "unfun" mechanic at best.