My family owns lots of cars some being restored and others on the back burner. We have several cars covered. Some cars never had coverage. The agents told us all the cars required coverage so we listened and got the coverage they told us was required to keep us legal. We never asked for or wanted fire and or theft coverage. It was told to us all cars required coverage and that fire and theft coverage was enough to keep us legal.
If you had led off with the information in your first post that the cars in question were in the process of being restored and or were not actually running you probably would have received better advice, quicker. It would have been clearer what you were upset about.
Obviously the agented wanted to sell you insurance for cars that were not running, whether you needed it or not. So he led you to believe that you needed it.
When and if you get any of the cars running, you WILL need liability insurance before you drive them at all. In fact, you will probably want full coverage for cars you restored.