Yes, I also agree this would be a significant improvement. The other thing is that it counts the person that leashed the monster as the person who tagged it, which makes it even more viable for abuse.

I believe hunt marks are already immune to provoke though, I may be wrong but they can't be initially pulled with it. At the same time, if whoever tagged it first isn't a tank in their tank stance, a tank with their tank stance up can pretty quickly pull threat if it has a decent amount of hp left.