Late versions of the F4F, the FM-1/FM-2, had only 4 mgs, but carried more ammo.
And the plane was used on escort carriers doing ASW.
The early version of the Wildcat the -3 had 4 mgs. The rest of the Wildcats had 6 mgs to the best of my knowledge.
Yes the FM2s were used on the escort carriers. Their slower landing speed and ability to take off with out need a catapult made them ideal for the escort carriers. The FMs also help to provide close air support for the amphibious landings which was another major task for the CVEs
And speaking of aircraft that did not have 6 .50s was the P-47 Thunderbolt which had 8 .50s in the wings.
The P47M model had only 4 mgs IIRC and had a top speed at altitude of 475mph!
One final side note. It was not unusual for in the field mods to the standard gun layout. Perhaps damage to a gun or the need to get more speed or altitude for a particular reason were some of the reasons.
Or in Pappy Gunn’s case if 2 .50s are good 6 or 8 is better:-)
Regards
alfa6 ;>}