Be an average to plus defender at 3B?
As a first baseman, he's not differentiated (results-wise) from a guy like McGeary. Yes, I'm aware of the difference between FB% there, but that isn't the only measure most people have for hitters. McGeary reportedly hits the ball a hell of lot harder, for example, and the performance numbers at AA are damn near equal.
Overall, just from a position player perspective, I'd have him definitely behind:
PCA - much higher total value with defense & speed
Caissie - better performance, three years younger at the same level
Alcantara - primarily based on the tools, but age / level comes into play, defensive value
Shaw - 1st round pick, has been really good so far in his first exposure to pro ball
I'd likely have him behind these guys:
Ballesteros - age / level, raw performance is better, 1% chance of sticking at C
Rojas - age / level, defensive value
Canario - louder tools, same age / level higher, better performance (when not rusty) last 18 months
Vazquez - defensive value is reportedly very strong as a plus SS, has hit very well this year
Triantos - age/level, potential defensive value as a 2B, contact rate
I'd have him in the same group as these guys unless I hear more about him playing a positive 3B:
McGeary - If they're both 1B's, it is a tossup who is a better hitter (yeah, yeah, fly balls, blah, blah)
Mervis - Another 1B, who has had a better season than either other guy (yeah, yeah, fly balls, blah, blah)
Aliendo - the defensive value is a big plus here as a catcher
Perlaza - He's doing now at 24 what Murray is likely to do next year at Iowa at age 24
Add in the pitchers and he's not really all that close to top 10 for me. Now, if I heard he's been playing a plus third base? That changes things and moves him up into that second grouping for certain.
Note - I've done this off the top of my head and I'm probably forgetting guys.