The reason the Fw-190A5 does so well is because a lot of pilots underestimate it, I usually see people who are not dedicated LW types that just wanna try a 190 for once usually goto the Dora because it has the speed and has a lower ENY meaning it must be better.
The 190a5 is left on the side where people who know how good it is fly it

The main reason it does so well i guess is someone sees it and thinks "oh a 190 this will be an easy kill" sucks for the guy who thinks that
