BGIF, all due respect, etc., but the first part of your post doesn't mean anything. Teams win in different ways in different years. Obviously the defense was not as good last year as it was in 2012, which is all the more reason why losing Golson hurt. In my opinion, going from Golson to Rees severely limited the offense. How those two played the previous year isn't relevant; player performance is not static year over year, especially college players. The reality is that, for all his merits, Tommy was just not as physically capable of doing the things Golson could have done, and that is why there was a big dropoff.
As far as your last paragraph, I think one of us is misinterpreting the question. I thought he asked whether losing those 4 guys this year would hurt more, less or the same as losing Golson LAST year. If that is correct, I don't understand what the 2014 QB depth chart has to do with anything.