That kind of thing is hard to say and I think a big reason why player "character issues" lead to drastically different evaluations and grades by teams before the draft. Judging how a person will impact the growth of others is pretty difficult unless they're a well respected veteran in which case the answer is usually that they will help that growth.

I think it really depends on how much Gordon himself has changed and his demonstration of that. If Callaway can see Gordon as someone who's really escaped from a Johnny Football-like purgatory, then he should be a positive influence. That said, the effect would probably be stronger had Gordon come back a year earlier and re-established himself as a top tier wideout or something. Ultimately it's really anybody's guess but I think Gordon will try to help him out, and Callaway will have to meet him halfway. Of course, you have to factor the other guys into this too and I don't really know what to expect from Landry any more