Do Khitomer restrictions on particular weapons imply that Federation and Klingon fleet size was also limited?
Short answerNo; limiting a weapon or a ship's characteristics is different from limiting how many ships may be built.
NotesQualitative arms control differs from quantitative fleet limitation. A treaty may prohibit a weapon or cap the characteristics of a ship without restricting how many qualifying hulls each party can build. Under the Washington treaty framework, the 10,000-ton unit limit for cruisers did not by itself fix their total number. The object of a restriction matters as much as the existence of a treaty.