The thing I don't think a lot of people realize about the C position is the mental aspect.
There were a lot of mental f*ck-ups on our OL last year and the year before that. A LOT. Yeah some of the mistakes were just undertalented and/or injured guys not physically being able to do the job but you look at how some of the pass rushes and blitzes were picked up (or not) and there was clearly a lack of on-field leadership of the OL which traditionally is the C's role. I just have never seen Garza having the mental capacity to grasp that part of the game. Plus I know Garza was flagged multiple times for false starts. C'mon man... you're the GD center and you're false starting?
That's where I think we need to get better at the C position even more than the size/strength/age stuff. Garza can snap the ball and block, but there's more to being a good C than that.