I'd probably go for that compromise number. 1200 just seems too
high, though 150-odd over nearly a century might be too low given the number we see in the Dominion War. I'd accept a thousand Mirandas, and even more Oberths though.
Also on the "President Sulu" front, when you are writing history, you generally use the form of address they would have held at the time, to prevent confusion. Hence General Montgomery at El Alamein, and Field Marshall Montgomery in Normandy, not Viscount Montgomery at either. Sulu wasn't President when he was captain of the Excelsior, so it would be pretty perverse to address him as such.