The dora only has massive engine power over the 38 (as its only true 'overwhelming' advantage) and higher speed retention (38 cant dive, level off and retain high speed as well as the dora does).
The reason why you see the 190d9 having better stats is for two simple reasons:
-D9 is not used for ground attack roles. P-38 is.. routinely.
-D9 is much more survivable as it requires a lot less thinking and skill from the pilot during a fight.
The 2nd point is perhaps the reason why most that face the 190d9 end up thinking its either an uber airplane or the pilot in it is very good.. when in fact its neither.
You see, its the same issue as the La7. The D9's engine and its massive WEP boost allows the pilot to compensate for the majority of his mistakes mighty quickly. The 38 instead, relies on its mix of abilities and benefits to make up for these mistakes (most imply shooting down the opponent rather than running away from it).
The mistake that d9 pilots are seen doing over...and over... and over again is entering a turn fight against a plane that is a much better turner than the D9 is. The D9 allows these mistakes to be corrected simply by diving with WEP on or climbing away after some separation is gained with WEP on. WEP WEP WEP. Without it the D9 cannot fix the mistakes of its pilots. Show me a D9 that is out of WEP and i'll show you a plane that wont survive the next dogfight it gets into.
This WEP however, does not make the D9 'better' than the P38. The 38 is a plane of versatility, a bag of many tricks and capabilities... where the dora has but the WEP trick and no more.
I remember a fight I had with Urchin a long time ago.. he was in his Dora (he was a 190/Ta-152 freak back then) and i was in my 38L. We went at it for a LONG time going from I believe it was 32k down to 12k before he broke off. As he was at d1.1k and doing his WEP climb away from me I shot him down.
Mighty piss match in chat and in forums after a bit.. he couldn't believe I could've shot him down from such range. All I could say was ... well.... neither could out-fly the other one but one of us had to win... and I won by using the one little thing my lil' 38 has that his vulcherbird didnt: flat trajectory, long range, nose quad 50 cal guns. I spent a good amount of ammo in short bursts (i didnt use tracers) as he did his lazy climb looking for the correct lead on the gun..when I saw the first hit sprite I emptied the 50 cal guns on him. 1400 rounds even at that long range the hits snapped his wing out.
As a 38 I could NOT run away from him. If I had he wouldve just turned his dora around and kept climbing while catching up with me at the same time then starting another round of that dogfight with me at a disadvantage. If i had dived his dora would've cought me in a worse situation. If i had simply followed him level keeping speed he wouldve gained alt on me anyway. This kind of things is what makes the D9 and the 38 different birds on their own right. a 38 pilot must be very aggressive and know his airplane.. the D9 pilot relies too much on his WEP to fix his flying problems.
Thankfully, Urchin has seen the light and has been known to fly the 38 from time to time