Since the cv patch of 2009, on NFNA it's been like this:

- aircraft stat determines attack and defense for SCOUTS (+ plane stats, obviously)

- fighter stat determines attack and defense for FIGHTERS

- bomber stat determines attack and defense for BOMBERS

If you look up "Adalbert's guide" under "Tip and Tactics" you'll find the same info.

Even using the search function would have got you better info than "urban legends".