At UW, you will get, as a normal part of the student body, at least a fair percentage of 6'3+ 280 pound OL dudes. They are everywhere in that area, and it's not surprising that some can function as walk-ons. It's 43,000+ undergrads, 50% instate (most are from the surrounding states anyway, i.e. Michigan, IL, Minnesota). So at worst they have ~10,000 males from Wisconsin to find talent from in the student body.
At UM, we don't have that luxury. Only 30% of our student pop is even from Florida, not exactly a hotbed of OL body types. We have 11,000 undergrads, and 47% males, so at best 1500 males to find talent from, and most are likely Hispanic/wealthy/nerds etc, not the 6'5 300lb cornfed boys or 6'1 CBs...