I was actually one of the ones who mentioned the height issue before Tveit was cast as Enjolras. It was when Jamie Campbell Bower's name was being bantered about as getting the part.
The real necessity for the character is that he have a commanding presence. He needs to be influential as a leader for the other students. Height doesn't really matter (Just ask Napoleon). Bower comes off as "slight" and "emo" to me. Not remotely commanding or charismatic enough to play the part. He may be 6'4" for all I know, but it has to do with his presence as an actor. He's dedicated and focused, yes ... just not commanding. I wouldn't want an Enjolras who "complained" and "whined" his fellow students into battle.
I think Aaron Tveit has the right qualities for the role, even if he's not super tall. Perhaps that's my own preconception, having seen the original Broadway cast, where Michael Maguire was at least 6'4" if not taller. He towered over the other actors on stage, and it worked well.
Height can also be faked on screen (just see film stars Alan Ladd or Nelson Eddy or Sylvester Stalone or Tom Cruise). Everything from boxes to lifts in shoes to calculated camera angles can help with physical presence on screen. But it's the personality that is the important thing. And I think Tveit has it.
Plus the boy can sing ... arguably better than any other name announced for this film cast so far.
"Jaws is the Citizen Kane of movies."
blocked: logan2, Diamonds3, Hamilton22