6'2" is pretty small. Like Young, he will struggle some with certain shooting PGs that are equally quick but taller. Also, I think Young was probably a bit quicker, although that's hard to say for sure.
I'm not knocking either player. Just acknowledging the obvious reality that, all other things being equal, height is a tough advantage to overcome in basketball. Lucky for Miller and Young, all other things are rarely equal. So they can use lateral quickness and quick hands to overcome a height deficit - at least in lots of cases.
6-2 is pretty average for a B1G point guard.
Top 20 players by Assists/Game, which includes the top guy from each program (only including players who have played at least 10 games... which only excludes 6-1 Andre Curbelo)
5-10 Fatts Russell (Maryland)
6-0 Joe Toussaint (Iowa)
6-0 Tyson Walker (MSU)
6-0 Sam Sessoms (Penn State)
6-1 Eli Brooks (Michigan)
6-1 DeVonte Jones (Michigan)
6-1 Jamari Wheeler (Ohio State)
6-2 Alonzo Verge (Nebraska)
6-2 Boo Buie (Northwestern)
6-2 Trent Frazier (Illinois)
6-3 Xavier Johnson (Indiana)
6-3 AJ Hoggard (MSU)
6-3 Da'Monte Williams (Illinois)
6-4 Jalen Pickett (Penn State)
6-4 Payton Willis (Minnesota)
6-4 Geo Baker (Rutgers)
6-4 Jaden Ivey (Purdue)
6-5 Johnny Davis (Wisconsin)
6-5 Sasha Stephonofic (Purdue)
6-6 Paul Mulcahy (Rutgers)
Of the ones we face on other teams, 10/18 are 6-2 or shorter (and 13/18 are 6-3 or shorter).
I don't think 6-2 is a significant disadvantage to overcome, though there will be some challenging assignments. I think Miller just looks short on our team, since the next two shortest guys in the rotation are Baker (6-4) and Harper/Mulcahy (6-6).