This isn't actually an issue.
It is when you have to consult tie in material or assumptions. Sure, the Emperor had decades to prepare for this but a fleet of this magnitude can't be hidden, no matter how good security is and how good your intelligence service is.
This fleet needs probably a million+ crewmen and officers to operate not to speak of gigantic space docks to actually build them and we are led to believe that no one in the galaxy even caught a rumor or found it odd that imperial Navy personell were retasked to a position and then dropped off the books.
However it is a minor quibble on a nerd level, i doubt a general viewer would care about such things. The movie had much bigger problems and many of them not its fault as it had to wrap a complete mess of storyline and inconsistency in a little over 2 hours. If they had pulled it off i would have been greatly impressed.
Daisy Ridley as Rey however kills it in this movie, her best performance to date but she also has to do the heavy lifting as it's basically her movie and the others are just background (especially Boyega who has been demoted to punch line speaker and a short personal story when he meets other Stormtrooper deserters).
Poe (Oscar Isaacs) is still an awesome character.. we learn he had a shady past before the rebellion (which Rebel didn't?) but the scene where he loses hope in the final battle after seeing his troops being annihilated was also quite emotional. Unfortunately the impact was lost as we know of the coming Rebel fleet from the trailers - Disney couldn't resist putting in the money shot of the big Rebel fleet in the trailers so we were certain the battle would be won (we would be certain anyway as it's Star Wars and the good guys usually win, especially if it's the final movie).
Finally i can also say something good about Adam Driver's Kylo Ren, who up until now was the most major disappointment in the franchise (but not due to Driver's acting). He should have been the next Vader but instead came off as a childish, anger management impaired idiot because he was written like it. This movie finally has him putting on some menace and gravitas which should have been there from the beginning (i was floored by the scene when he stopped the laserblast from Poe in mid air - that was badass). I rolled my eyes however when Kylo and Rey kissed.. why for god's sake? Was this supposed to a romantic kiss then where did this come from (i never got any underlying sexual element in their dealings)?
Him dying by sacrificing his life force for Rey was cool though.. it would be hard to explain to people how this mass murderer is suddenly a good guy and should be accepted, the same proplem Vader would have had if he had survived back then.
