Fizer would eat Garza's lunch. Those two aren't even comparable. I'd take Tinsley, Grayer, Hoiberg, Ejim, Niang and Morris over Garza as well. All better all around players.
He's an elite college player but this "best player to step on the court" for Iowa or in the state is really overblown.
If it was just purely offense or scoring he probably is the leader if you value 4 years of production, although per game Fizer, Grayer and a few others were similar or better in scoring too. As someone else mentioned when you look at someone like Grayer being an elite defender there's that too. I was a little too young to remember what kind of defender Ronnie Lester was but in terms of carrying a team to winning things he is up with Fizer too.
When you look at all around production and leading a team to conference titles, conference tournaments and NCAA tournament success it's really hard for me to not laugh when people act like he has been a better player than Fizer. Fizer checked pretty much every box, he would have been a very high pick after his sophomore year and chose to come back. Garza would have gotten zero NBA interest after his sophomore year, and probably a late 2nd round pick after junior year.