I would never question an Admiral, but let me make a last pitch.

There are two types of charterers: those whose dinghy engines have failed, and those whose dingy engines are going to fail. In addition to convenience (more options), time-saving (no double trips), more freeboard (increased safety and drier bums), two dinks provide redundancy (less stress). You know your trip is not going to be interrupted by a complete lack of boat-to-shore transportation.

I don't know the ages of your crew, but our dinghy mates were the 8 and 12 year old boys in the photo below.



Each was assigned one of the dinghys, with the tasks of making sure it was drawn up and cleated off at appropriate times, tilting the outboard up and down, drying the gunwales, tying it off to a tree or rock on shore, etc.

Just sayin' I think you would find the advantages far outweighing any downside. Whatever, have a great time!