Maxperson
Morkus from Orkus
I'm kinda okay with that, but your suggestion is certainly more flexible, so that's also worth considering.
My view is that if I'm going to narrow the use of counterspell to the point where it won't be used, I might as well just get rid of the ability. I think if it's going to exist, then it needs to be in a form that is at least going to be used sometimes.