Thank you, Bob, for emphasising some aspects.

Serviceability, MMH/FH? Yeah, isn't that one of the main benefits
(critics would add: not many) of switching to all-Hornet air wings?

Personally, I have always believed the number of 12 aircraft per
squadron was used, because it was very easy to divide into pairs,
flights of 3 or 4, and also easily divided by six (for example, when 3
pairs of Tomcats were required for a CAP at the time).

Now sources vary on this subject:
some say: 12 a/c for F/A-18 sqn and 10 a/c for F-35/JSF sqn,
other say: 10 a/c for CV-based squadrons, 12 a/c for land-based,
or: more than 10 F/A-18s per a squadron, but only when they provide the
air wing with tankers...

Best regards,

Jacek