Why not keep eny, but change a few of the eny values of a few planes and vehicles. I'm not advocating placing a higher eny value on all the uber planes and vehicles, but say a couple to keep both sides somewhat happy. Just a thought that could be tried and implemented to see how it works out. Besides 2 countries kicking the crap out of the 3rd country, having no restraints on the most populated countries is like pouring gasoline on a fire. Whether you are Bishop, Rook or Knight, you have experienced being rolled by the other two countries. It's even worse when your country has a very low population and there is no eny. I understand the frustration that a player has when their combat choices are limited due to eny. I've experienced it many times in my 20 years or so in the game. Taking my own situation aside, some sort of balance adjustment is both good and fair for every country. That is why I am proposing some slight changes in just a couple of the eny values of planes and vehicles.
Cheers, One-eye