After looking at the config files for the aircraft only the Hurricane and swordfish are set way beyond their Max combat radius. Most likely done to make aircraft a threat early in the war. Nevermind aircraft where only a minor threat to UBoats early on a good day for the RAF. I've had two carrers ended by single hurricanes catching me on the crash dive and have taken several painfull hits.
The P-38J's 1200 Km combat radius could be too high but I've yet to run into one. If it doesn't carry bombs then 1200Km is about right.
Sunderlands, B-24s and PBYs combat radius in 1.4b are pretty close even erroring slightly on the low end of the scale. The B24's loadout seems to be a tad overkill at over 8,000lbs, these planes normaly flew with bomb loads between 2,000 - 4,000 lbs on ASW duty.