Have you ever read the book "Fighter Combat" by Robert Shaw?
It is a good read, it might dispell some of the illusions you have about a "knife fight" between a 190 and a Spitfire IX being any kind of close affair.
One thing you have to keep in mind is that in the real WW2, pilots were even more timid than people are in here. There was a good reason for this- when they screwed up, they actually did die.
So what a Spitfire pilot might describe as a 190 aggressively boring in, I would probably describe as "The 190 came in with a 5,000 foot altitude advantage, made some bore n zoom passes (being careful to roll out and "extend" in the opposite direction of the Spitfires break turn), and then left when he started to lose his energy advantage.
A 190a5 or 190a8 does not have a significant advantage in the vertical if both planes (the Spit IX and the 190), are going close to the same speed. A 190 going 400mph will outzoom a Spitfire going 300 mph, and if a real-life pilot was smart enough to keep his energy up, he could probably make 4 or 5 "Boom and Zoom" passes before he had to split.
Another thing you must keep in mind is that a WW2 "furball" on the Western Front commonly consisted of perhaps a squadron on either side constantly seeking a height advantage to bore n zoom from. Sure, the two sides were in sight of each other, and if they were of a mind they could have engaged, but as a general rule even the most aggressive pilots would not engage unless they had altitude, numbers, or preferably both. A group of 190s could undoubtedly engage a group of Spitfires and emerge the victor, even if a handful of 190 pilots got a little too agressive and engaged without having a clear energy advantage- because those 190s had other 190s to bail them out of trouble. Unlike in Aces High, living was the highest priority for the vast majority of pilots, not just "getting a kill". After all, there is no reupping in real life.
In real life, as in Aces High, top speed is a very important attribute. A plane with a higher top speed can typically cruise faster than a plane with a lower top speed, thus picking and choosing their fights. In Aces High, unlike in real life, the MOST important attributes a plane can have are (in order, in my opinion) a small turning radius, a fast turn rate, and good acceleration. The Spit IX has all three. The 190A has 1 of the three.
I have no doubt that the Spitfire and 190 are modelled correctly vis a vis each other in Aces High. Yes, the 190a5 may be lacking 5 mph of top speed on the deck. It honestly doesn't matter. As it is modelled, a 190a5 (or a8) holds the advantage over a Spit 9 as long as the 190 pilot is exceedingly cautious, good at maintaining an energy advantage over a lower and slower opponent, and knows when to run.
I think you just have an unrealistic portrait of what a "fight" was like on the Western Front during WW2.