The thing is; there is every reason it would work.
I have been mocked for stating it, but it IS a true thing (and has been shared by others elsewhere); it was called "the Goblin rule". The worst thing in the game is (was, now) a Goblin. The idea was that the dollar price of models was weighted by how many Goblins there were "worth" in game. So, elite models were more expensive than basic troops - even though the amount of plastic and level of sculpting was the same.
Many people have said - and I would agree - GW has always been more concerned with finances than getting points values right. So, the price of a model might very well be a better reflection of its value in the game than a points value assigned to it.
And, with a lack of points in AoS, this might be one way of looking at balance.
I wouldn't insist on it, but it certainly sounds fun.