That all makes sense, and I guess I agree on all points. Not knowing anything about the RAAF's resources (or the buyer's feelings on the deal), I would have leaned toward selling half and keeping half in a reserve capacity if it were at all feasible. If you need a reserve, you probably need it really badly, and it's not exactly unfathomable that the fancy-but-fragile F-35 might be grounded someday because of some automotive airbag recall-like "whoops" screwup by the manufacturer.

edit: it looks like you've still got two squadrons of Super Hornets until 2025, so you've got that going for you