While the post season could certainly skew the results, I think you can make a pretty good argument for each of the choices above:
Zeke - Leading scorer and intimidating defensive presence
Nik - Second leading scorer and leading rebounder
Alex - Third leading scorer, top assist man, the engine that made the Zips go
Brian - Leading 3 pointer shooter (by far), good ball handler, terrific rebounding guard
Quincy - Most versatile player on the team, good scorer, good defender
Tree - by request