It's really a mess of contradictions.
it is. Each set of authors was free to extrapolate on the only example they had: M'Ress.
Don't sweat it. Invent heights that will be useful for your game.
these numbers had to be stated somewhere else.
No, it could have been someone working out that M'Ress was "shorter than Scotty". Memory Beta
is compiled/edited/reedited by hundreds of Trek fans and not every change is necessarily accurate to a specified source.