Could the United States have secured the 8-inch gun limit while Britain obtained a 15,500-ton cruiser limit?
Short answerVery unlikely without a large built cruiser to justify 15,500 tons. The 8-inch gun limit itself came from rounding up the Hawkins class's existing 7.5-inch armament.
NotesThe 8-inch limit did not begin as an American negotiating target. The Hawkins class carried 7.5-inch guns, and rounding that existing armament upward supplied the eventual ceiling. A 15,500-ton cruiser limit would likewise need a sufficiently large ship already built to justify the figure. A working design therefore mattered more than a preference for a particular number on paper.