I'm all for something along these lines, as I've suggested a somewhat simpler, yet similar way to address this existing problem in the 1.3 patch thread.
I still find it odd that so much attention was focused on champions in LH, yet powering up henchmen (along with other various methods not involving champions) still proves to be a far more efficient option. As it is now, capping recruited champions at a meager level 9 is strange enough, then to reintroduce champions at even lower levels in the late game (when all my main units are at least in their mid-20's) is quite frankly, lunacy imo.
I know some like to "craft" their new low-level champions through power-leveling late game (while I'd consider it little more than tedious hand-holding at that point). But as a game that tries to highlight champions as something worth having regardless of your play-style, I truly hope this gets addressed at some point soon.