I think Garvin is a legitimate D1 point guard, as a backup. 15 minutes a night to spell the starters and not hurt the team while he's in, an occasional start when someone is out.
I think Tavari will be in time a good starting D1 point guard. Oddly, the Zips success this year may have slowed his development as being in contention forced the Zips to keep the veteran guys on the floor. It was no time to experiment or prepare for the future. Clearly, Groce likes point guards that cab score the ball and Tavari has shown an ability to do that.