It is overblown under Self if you don't do much else to help the team. Joe was an athlete as well but didn't know plays and wasn't skilled enough to stick at this level. Udeh is an athlete, raw and unfinished but he started figuring out how to use his gifts towards the end of the season. His athletic ability carried him while the rest of him tries to catch up. We rarely saw any of MJ's athleticism, not that he was healthy or engaged anyway to care.
Timberlake athletically isn't elite, he's not below average either. He has an elite spot up shot but inside the arc he's very athletic when shooting off the dribble etc (gets high in the air before releasing the ball, making it very difficult to contest). He can play above the rim in transition. I think he's more athletic than JCL or Moss that came here with similar size and shooting prowess and came off the bench. Both just knew how to get the ball in the hoop doing what they do. I have no clue about his defense, passing or other fine details of his game but on offense its easy to see his high level of BBIQ and skill which is a take no matter what imo.