That's kind of silly. Fourth Fleet has zero permanently assigned ships, and a peak strength of something like four ships in its area of responsibility, and doesn't, AFAICT, involve any more naval strength typically deployed in the region than US Naval Forces Southern Command had in the region prior to Fourth Fleet being stood up with the same area of responsibility and commander as USNAVSO.
AFAICT, the "intention" of standing up Fourth Fleet as an organization was to bring the naval side of Southern Command HQ structure more in line with that of the rest of the geographical combatant commands (US Naval Forces Africa still doesn't have a numbered fleet or similar command associated, but Africa wasn't yet a full independent unified combatant command at the time Fourth Fleet was stood up in Southern Command.)
AFAICT, the "intention" of standing up Fourth Fleet as an organization was to bring the naval side of Southern Command HQ structure more in line with that of the rest of the geographical combatant commands (US Naval Forces Africa still doesn't have a numbered fleet or similar command associated, but Africa wasn't yet a full independent unified combatant command at the time Fourth Fleet was stood up in Southern Command.)