Also your proposed solution would create all sorts of difficulties, for instance deciding who gets to use what engine, so I think the cure would be worse than the disease.
At the moment there isn't a problem, but if you severely restrict aero, then the engine and kers become the most important aspect and then you don't wont everyone with teh same power plant. Although a lot are running cosworth engines.
What do you mean teh difficulties of who gets what. nothing has to be deided. It's who ever the manufactures want to sale it to. Just a limit on how many teams they can supply.