As a tank main, I can honestly say that if you or the tank you have is competent, regen on pulls is perfectly fine, especially with larger pulls. As a tank, if you plan on doing large, multi pack pulls, you shouled ALWAYS use your aoe emnity skill on pack before moving forward, isn't hard and you can do it whilst moving so there's no reason not to. That Regen could be the thing which keeps you up and running during large pulls, don't be an idiot tank.