ENY's will need serious review before used in this context. There are plenty of high ENY aircraft that are as good as, or some would argue better than, their low ENY counterparts. (P51B comes to mind). will be interesting to see in practice but, if the people who have no intention of switching sides are happy with the plan, I would not take that as a good sign.
off topic - I still wonder about applying the perk balancing formula also to scoring. Then you would have something that has a real day to day impact, on arena balance and also plane types. Seems like it would be a lot easier to do (1 plane getting a kill against bad odds should be worth more than a killl with 10 friends anyway, and nowhere is this yet taking into account.)