It may be an opinion but I think it's a pretty safe one and if you asked the coaches, i'd bet you a large sum they planning for the other 4 to be immediate contributors with a good chance at being day 1 starters and Collins providing depth. Collins will very likely be rated the lowest of the 5 by the recruiting services that re-rank transfer. Not to say they are the be all end all but I don't exactly think I'm going out on a limb on this one. I think that's pretty close to a board consensus.
As for what makes this different from big school guys who rode the bench, past guys like Carroll or Dylan Wright have been much more highly rated as recruits. They also had better talent in front of them and were younger with more years left than Collins. Or guys like Filiaga and Pinckney actually played at those helmet schools. We essentially already know what Collins is, a backup caliber DE at the P5 level who will be a nice depth piece. And I'd argue we already have a pretty good idea of how good Crooms, Selig and Spencer will perform as well. They already have proven themselves at the FBS level with several performances against the P5 and i'd argue if you are skeptical how they will perform at the Big Ten level then you are overstating the difference between the G5 and P5. Being an All conference player at a G5 very likely translates to at least quality starter at the P5 level.
Now with Henderson, going from a middling FCS conference to the Big Ten is a bigger jump where I think it's fair to question how his game would translate but the reason why I think we have a good chance at that happening is due to the fact that Henderson has a better resume than Gibbens, Baugh and Stapp did, the three other FCS guys we recruited, two of which became quality starters and a third that has shown promise. None of those 3 were ever first team all conference and Henderson was and Henderson also had higher PFF grades than those 3. Also better production as well.
In general with transfers, I do think for most guys, we have a very good idea of the type of players we have on our hands, especially experienced guys at the FBS level, and we have had very few transfers under PJ where they didn't perform close the the level that we expected from them.
Anyways my main point with Yah-E was not that I have a problem with him being more excited about Collins, although I disagree with it, but his reasoning behind it. I think had he been more specific about Collin's game and production relative to the others, he'd have a better case but he cited nothing more than the fact that he is a P5 transfer and the others are not. There have been times i have been more excited about P5 transfers over more experienced guys at lower levels but it was not solely because of the levels they played at.