not sure what your trying to prove here, P was for pursuit, for obvious patrol planes like the PBY, PB2Y, PB4y. PB standing for patrol/bomber. The F for fighter designation did not become implemented until after WW2
because(i think) the p51, 47, 38, etc., were originally intended to chase down bombers, escort our bombers, and chase bad guys away(hopefully)......thus the "pursuit" designation. that's also why in reality, these aircraft had such a hard time in a tight turning fight with little wiggly things like the me109, zeeks, etc.......the f4f could sorta kinda handle zeeks, and i think the f6f was designed specifically to fight the zeeks.
i could be wrong though.....