[PeterVerney]

There are so many variables in an actual combat situation that performance graphs, valuable as they may be, are only a factor.
Pilot skill comes first, initial attitude, i.e can acceleration be got by diving. mishandling controls can loose speed, firing guns, especially the cannon, soon knoks off a few knots, wrong setting of rad flaps. I could go on, but it comes back to the pilot in general unless the aircraft are seriously mismatched.