Faking movement via camera projections

Because of a several weird constraints I have an unusual issue.

I have a variety of platforms. Let’s pretend they are boats.
Because of internal mechanics of the boat (e.g. pathfinding and other things of crewmembers) I want the boats themselves to be immobile/static. It makes a lot of other things easier.

However out on sea, and in combat, they should be able to (appear to) move around.
So I was thinking I’d have off to the side somewhere all the ships in their static locations, and have a camera above them.
Main combat at x = 0,
ships are actually located at x = 10000 outside main world.

Then back in the main sea x=0, I will have a bunch of quads rendering exactly what those cameras are seeing. Thus I just have to move these quads. (Sorta like how Portals are typically implemented?) Then if a missile were to hit one of these “quads” I would just teleport that missile to the respective location of that ship, and then although the user wouldn’t know it, the missile would have been moved (again like portals.) Thus achieving static ships that appear to be moving to the user.

So anyways, aside from having a bunch of hidden “portals+greenscreens” everywhere. Is there any potential issues with this approach or a better alternative?
e.g Post Processing or artifacts or anything I should be aware of before I invest the time into developing this approach?
e.g. Having to deal with the fact that I won’t have 1:1 portals, but need some kind of Green Screen behind the ships, for quad to show whats in the real sea, and not whats behind the actual ship.

I know a variety of games leverage something like this with a few cameras. Like in counterstrike, I think they put some of the background as a relatively small object outside normal map, and just attach a camera there, to mimic a skybox type thing, but with objects.

But to have have every main ship having this done, I don’t know of any. I would likely have on order of 10-50 ships most likely, so probably would need >10 but <100 total cameras&quads.