Then again, it is certainly worth pondering what "British" means in the Trek 22nd century. There's a whole range of things, from Picard theoretically being French while being so British, to Cambridge badgers apparently being overrun by skunks.
Whatever be established about "the Royal Navy", it shouldn't affect our ponderings of United Earth or its military much. Every reference to the Royal Navy predates the year in which United Earth finally earned its name, after all. While many things such as UESPA and UESF explicitly preceded that year by a wide margin, a lot about their status may have changed in 2150 sharp, rendering evidence from before that date moot.
Timo Saloniemi