This is good. This happens on any good basketball team. Jaylen needs a little bit of that edge. As a SF, he will definitely have to defend guys bigger than Smart who will be happy to knock him on his butt and not have a nice discussion about it afterwards.
I agree with triboy that Jaylen should have dunked on Smart after that play, not walked off the court.
Also: Since when is this considered a fight? I (think) I saw them both flash smiles. Smart relishes in the competition. Jaylen seemed to try to dismiss it and go, "That was a charge, hahaha." When Smart laughed at that, Jaylen walked away. This is one teammate helping toughen up another.
https://m.youtube.com/watch?v=oriLx8SOwyIWe need a little more Amar'e Stoudemire and a little less Shane Battier out of Jaylen.