If you had a ship on every possible space, they would have a 100% chance of landing a hit, so by your logic this would be worse. But it would take 100 turns to sink you, which is the best possible outcome.

Having only one 5 space ship is objectively worse than having one five space ship and all the others. Unless of course you also created a new rule that they have to hit the same spot multiple times, once for each ship.

At that point you’re just playing Calvin Ball, though, and you might as well put the ships under your chair and claim “You never said floor!”