How far the United States might concede at Washington

What concessions might the United States have made to secure British signature on the naval treaty?

Potentially a larger British capital-ship and carrier total, especially if Britain framed it as the minimum needed for three ocean fleets.

Britain might have secured a 10:7:4 ratio, twenty capital ships, and ten carriers. Another possibility was accepting a less favorable ratio while winning a total of roughly twenty-five capital ships. The negotiating logic is operational: Britain needed enough hulls to sustain three major fleet concentrations, and the United States would have had to accommodate that requirement to secure a workable agreement.