Most likely the first few dozen Starships will not be re-launched in any short time. Although, the engines from any that land could be bolted to a new hull and re-used, after a week or two of re-work. There is simply zero plausibility of the current tile system offering any sort of quick turn-around.
But that doesn't matter. Even without any Starship re-usability (aside from Superheavy), you still come out far, far ahead of any conceivable evolution of SLS.
Their own deliveries of fuel and client payloads will be delayed from the airspace and downrange surface exclusion zones.
Once you've got vehicles in space you'll need 24/7 monitoring and management. Even if mission control teams are relatively small the only way you'll be able to safely manage a large number of missions will be with a large number of teams.
The personnel and infrastructure costs will put a cap on the number of Starship launches SpaceX will ever be able to manage. The costs of those will push up the costs beyond Musk's low-ball fantasy promises.