Scenario fighting is significantly different than 1:1 Main Arena fights. Scenario fights are typically many-on-many, start at much higher altitudes, involve only historical matchups of planes (not whole plane set), and do not have the benefit of knowing the exact environment you are going into (thanks to no or much-less radar information and less certainty on what the situation is). This gives significant changes to fights.
One example is how good 190's are in scenarios as a result not of great turn rate but good speed, sturdiness, very crisp and precise roll and pitch response at speed, ability quickly to go from one shot, to re-targeting, to another shot, with lots of lethal ammo. Before flying them in scenarios, I thought they'd get dominated by Spitfires. They don't.
One plane that, to me, suffers a lot in high-alt scenarios is my beloved P-38. It's low compressibility limit and severity of compressibility effect make it very challenging to fly in scenarios, although if you can handle that, it can still be a decent plane in that setting because of its various other traits.
I remember watching some ultimate fighting back when it was a new thing. One of the fighters (Tank Abbot) was talking about fighting styles and disparaging the guys who get into grappling. He said something to the effect of, "Yeah, you can use that in these one-on-one cage fights, but if you try that in a real bar fight, while you are rolling around on the ground, some other guy is going to come up and smash a bottle over your head." That's how it is for scenarios.