In reality the FW-190A8 should be the best performing FW-190A IMO.
1. It did gain weight but it gained a lot more horsepower. The FW-190A5 wing loading for a jadg-einsatz with full wing armament is 46lbs/sq. ft.
The FW-190A8 with a full wing armament is 48lbs/sq ft and it gained 200hp.
Look at the Spitfire Mk IX (35lbs sqft) vs. the Spitfire MkXIV (40lbs sqft). The Spitfire Mk XIV turns the same radius as the Mk IX according to the tactical trials and it gained lots more wing loading with a very little increase in Hp. Both the Merlin 66 (+25) and the Griffen 65 are 2050hp engines. The Spitfire Mk XIV had a better prop and when the Griffen was approved for (+25), which I think was post war or very late war, it had a better thrust to weight.
2. The FW-190A8 had improved ailerons, elevator (they got rid of the crappy looping elevator design used in the previous models), and better props over the FW-190A5. The ailerons and elevator had different designed hinges and spacers. The FW-190A8 had three props a pilot could choose from.
A standard metal bladed prop, a wider chord wooden prop, and the really wide chord prop used on the Dora (late war).
The FW-190A5 could only use 1.42ata @ 2700U/min for 3 minutes and it still retained advantages over it's contemporary allied fighters.
The FW-190A8 Jagd-einsatz's should out zoom, out dive, roll as well or better, outturn, accelerate as well or better and generally be more nimble in the air than the FW-190A5. All with much better armament.
Crumpp