I like the idea but I would only change that if you can't remove a ship and be at 2 or more ships after having your fleet built, then your stuck with the ship your with. This will prevent people from purposely making their fleet illegal just to redo the process because they don't like the fleet.
I think that rule is already in there. "A player may not dismiss a ship if it would result in a squad of fewer than 2 ships." So you are stuck with at least 2 of the ships you draw. Your deck would be declared illegal before you drew your ship cards if it were not possible to field at least 2 ships. So that shouldn't be a problem, unless I misunderstand you.