The drawback, of course, is the risk of our gunboats getting hit from the air. So far they've given as good as they've got from air attack, and the enemy air force is pretty chewed up and so may be reluctant to sortie heavily after knowing they've driven our air force out of the picture.
Bear in mind that one of the F-16's weapons of choice is the Maverick antitank missile, and Mavericks are pretty much ideally suited to being used on ground targets in large numbers. If one or two of those actually hit one of our gunboats it'd probably leave the poor thing dead in the water if not sinking.
By now they must be very aware of the gunboats as a threat to them, and while they're probably too politically correct (heh) to say anything about it the Commonwealth Navy is likely picking up boogeyman status in their eyes to some extent. I expect them to make some serious effort to sink our ships every time they get firm information on their whereabouts while having the air assets to do anything about it.
[Unfortunately, Toledo's airports are awkwardly far inland and we may not be able to hit them with gunboat attacks without sailing dangerously close to shore or straight up the Maumee River, at which point we could easily wind up trading shots with enemy tanks at close range. Not so good.]
Yeah. Now we're seeing why that was a -2 CP option at game start.
One thing I hope we're doing, and that our land forces can/should do, is push technical patrols as far south as possible to at least see the Victorians coming if they've already started their march.