I did a few runs in a Dora tonight. The thing is a monumental pig if you don't have alt to work with and the climb rate isn't that hot.
Eh?
The climb rate in the D-9 eclipses most of the LWMA plane set. Alt-X it, hit WEP and even with 100% internal and a drop tank, you'll climb like a raped ape.
While I don't particularly care for the D9, I have flown it enough to realize its pretty far from a pig. The A8 is a pig. The Dora, by comparison, is a very capable fighter if flown to its strengths. Even without altitude, E recovery (acceleration/altitude) from co-E states is better than most of what you ran up against per your post.
With nothing more than a 1-2K altitude advantage, I find that the D9 can linger on the edges of a furball and engage and disengage, essentially, at will. Even if you get caught in a low speed, co-E engagement, you should still be able to gain vertical displacement against most aircraft, consistently.
Try your test on any night other than Tuesday. You wont have the 25,000ft Club to contend with and your choice of engagements wont be limited to 10v1 or 1v10.