Wow! I didn't expect this
The idea I had behind this, was that people often complaned about very little performance differences between aircraft. Especially online. The reason is simple: If you have a plane which is, let's say 2km/h, faster then your ennemy, he won't run away because sooner or later you will catch him. And this happens quite often online because you don't have to worry about fuel, getting in a dangerous situation, leaving your wingman alone, damaging your engine etc. If everything fails: hit "refly".
That's why random performance (+ or - 3%) could bring a little more realism to the game because planes with little difference in perf. would be seen as equal. Like in RL. In the game, a very slight difference is considered an advantage because you know you have these 2km/h no matter what.
Btw. these 3% where considered to be acceptable in RL if I remember correctly.
Of course we need to have RL performance as a base for this calculation. So one step at a time, but I think it would help the game in the future and calm down the FM discussions over ridiculously slight differences.