If they are that far below average it does not matter what they fly.
ENY does not affect your chances of success and does not prevent you from flying a specific model. It is only a rather weak incentive to make you switch sides in case you get hit by ENY often during your regular playing hours.
I don't think ENY is to make people change sides. Hitech said this....
"The value chosen is base on the damping effect of oscillation do to players changing side along and with desire to keep the time long enough that an immediate change and change back can not be used for a strategic advantage."
here. The "option to switch sides is there for those who MUST fly a P51 when ENY kicks in. The biggest complaint about ENY is not being able to fly the plane they want.
In cases like semp and Fess the Pony is their ride of choice. Not because it is faster, or turns better or carries more ord, it's because they like flying that plane, much like Ack-Ack likes his 38. Unfortunately most other players don't play for "history" and so fly a plane that peak an interest. More players today fly a plane to get the job done to win the game. That means the fastest, easiest plane with the best load out. Which also happens to be those that get cut out first when ENY kicks in, and so the complaints.
ENY would be less of an issue if the numbers were tied into more parameters in the game, two forces fighting one, or a local ENY setup or some such thing. Just population isn't accurate enough. It would also be less of an issue if players learned the game better. Learned that an LA5 is just as competitive as an LA7, or that a P47-25 is every bit as good as a pony when it comes to moving mud. These "gamers" who do nothing but look for and use the quickest easiest route to the win aren't doing themselves any favors.