No one in my offices teaches the c-clamp......
We try to spend the extra time to fix some of the issues people end up with, the c-clamp being one of them!
I really can't understand why the c-clamp still gets taught to people on a semi-auto. Back when the conversion was taking place, I guess it was easier to do that that teach a whole new grip from the revolver.
But when you're teaching a new user, do it right the first time.
That of course is my own personal opinion and may not fit the 'vision' of the organization......