I agree with you, K/D ratio is right way to show who are the better and who is only uraaaaaaaaaaaaaa style player.
This is not true, If you want I will show you that If you are fly in Su-27 you can kill more migs. Id depends on how you fly with this plane. I know that If we fly in mountains lowfly, best way is use migy but, there are still ways how to use flankers against this lowfly migs.