Yeah, I'm with the others. House rule as you like, but in my opinion, this way lies madness. The fact that they are giving one only certain select proficiencies when mutliclassing (and I think we can easily guess which ones aren't included) shows that they're trying to keep this kind of stuff to a minimum.
Could be, I was just offering a suggestion. Until the PHB and some playing is done everything is really just speculation at this point. I just hope they keep my option for an Arcane Archer feat available
