It is quite possible for all the opinions to be correct. When you outnumber the enemy by 7 to 1 its possible you rarely see them and so proceed unmolested enjoying the controls and radio. When you meet the enemy late in the conflict and he has only a few hours training maybe you do have the upper hand. In other circumstances meeting a trained pilot on a 1 to 1 basis you are in a very bad position.But... but... HOW can that be SO? We have data that PROVES the P-39 was superior, especially in climb, to the the Fw-190!!!