tottigol wins the obsolete Navy trainer trivia contest for the day!
I probably could have stated it more clearly, but the F/A-18 guy didn't get multiengine as a rating because of the F/A-18 (at least I don't think so), but because of the T-2. Most naval military equivalency ratings done to the Commercial Pilot level in the U.S. are completed at the level of the trainer prior to the fleet aircraft. T-44 (King Air) for the multiengine guys, TH-57 (Jet Ranger) for the helicopter guys, T-45 (now) for the jet guys. In the past, the strike guys all got multiengine centerline thrust ratings because of the T-2, even the Harrier guys, which I am aware has but one big fat engine.
The exception to that general rule is the V-22. My info isn't current, so I may be incorrect, but it was that way for many years, and I have no reason to think that it may have changed.