To go back to Mr. Choi's earlier comment about the rule of three—which isn't so much a rule as it is a practice and a guideline for developing force structure—the minimum you need to have one of anything available to you permanently is three. With two plus one, you're at the bare minimum, and if you want any more flexibility over the long term to accommodate things such as maintenance or any unplanned problems you might have with a ship, then any greater number than three gives you the flexibility of having at least two available to you on a nearly permanent basis.
On April 8th, 2022. See this statement in context.