Boomer, I agree with you about the basketball players. However, I think it has more to do with hip/foot position. Working for hours and hours on rebounding drills against people that are taller, weigh more or are stronger than you, the good ones develop a knack of where to place their hip on the other guys body to control what he can (or cannot) do. When receivers, in particular tight ends in the contact zone, can establish good position on the defender with foot and hips on the defender and between him and where the ball is coming from, the defender cannot get around him until he separates.
I don't think that it's a coincidence that the two best TE's of this era (Gates and Gonzales) played college basketball. You can find big athletic guys anywhere to play tight end. These two stood out. Jimmy Graham, another example. And I don't know anything about Gronk-a-douche......other than he bangs porn stars and posts pics on twitter.