It's very important because you don't need 500 artists to make a fighting game, in fact more, unique content creators means the leads will have to go over more content to bring it all in line with the art directiion, because all of it is so in your face and obvious.
MVCI already has the majority of osaka studio developing for it, adding another 50 artists isn't going to do shit unless they are just making props/enviroments.
this collides with the reality that game companies shift people around for crunch all the time. it happens a ton. if anything it is even easier if both MvC:I and SFV are developed in Osaka, and it is even easier if the SFV team is smaller than the MvC:I team and is even even easier if the SFV team has loosely defined release dates but MvC:I has a hard release date and a contract with Disney
besides, it is obvious that SFV and MvC:I were highly parallelized. Again, the difference between characters is stark. the leads clearly had their hands full and could not bring in line the characters. this happened in SFV too. (some of?) the characters were outsourced, and while the difference isn't as big as in MvC:I, it is still there. the DLC costumes are also very different in quality from one to the next. Guess why
everything you are saying goes against the obvious reality that MvC:I looks like it was put together like your old group projects in middle school.
you make Chun, and I make Ms Marvel, we put them together in the game the morning before shipping the demo. what can go wrong