Using the Navy as an example since their aircraft fleet is somewhat more simplistic than the AF, historically there were a lot of different airframes on carrier

Using the Navy as an example since their aircraft fleet is somewhat more simplistic than the AF, historically there were a lot of different airframes on carriers. The iconic 80s cold war fleet was a mix of the following: * F-4 - older multirole fighter, SEAD/STRIKE/CAS * F/A-18 (A/B/C/D aka legacy hornet) - replacement multirole * F-14 - interceptor * A-4 - strike, SEAD etc * A-7 - strike, SEAD etc * A-6 - strike, CAS * EA-6 (significantly different from the A-6) - ELINT/EWAR * E-2 - AWACS * C-2 - COD * S-3 - Anti submarine, Tanker These were pretty much all replaced in the mid 90s leaving the following: * F/A-18 (E/F, basically a different airframe) - multirole fighter, SEAD/STRIKE/CAS and Tanker * EA-18G (basically the same airframe as the E/F) - EWAR/SEAD while retaining marginal A2A capability * E-2 - AWACS * C-2 - COD That's a pretty drastic reduction in airframes to manage so it's understandable why those managing them want to try to maintain consolidation to an extent. Now whether this is the best way of going about it is an open question. The F-18 platform has shown that it's possible but it's also much more mature, having had many decades to work out the bugs. There's also the question of how they managed to talk the navy into a single engine platform but that's a rant for another day... Note: the first list was never all deployed at the same time on the same carrier AFAIK. They travel as squadrons between carriers depending on the carriers mission. The second gets deployed together regularly as they comprise the bare minimum for an operational air wing.