One cursory look at Michigan's 2013 recruiting class shows five offensive linemen, including two (Kyle Bosch and Logan Tuley-Tillman, both grade-A mashers) who graduated early* and are already on campus. Five is a lot of offensive linemen, especially considering that Michigan went with four OLs in 2012 as well.
Now, there's no position that's as redshirt-heavy as offensive lineman, and for good reason; the number of linemen who can step onto the field at a Big Ten level as true freshmen is exceedingly rare, what with the gains in playbook study, strength and experience that a player typically needs to go through. Even in the unlikely scenario that a prospect is physical enough to step onto the field in his first year, can he be counted on by his teammates to know not only what he's supposed to do, but what they're supposed to do and work in concert? And is there nobody in front of him with more refined skills?
We bring that up to establish that offensive linemen are generally five-year collegians, and to be around for only four years or fewer is the exception, not the norm. As such, gathering 4.5 scholarship offensive linemen a year is a pace for spending 22.5 total scholarships on offensive linemen. And the line is important, but it's not "quarter of all scholarships" important.
So why's Michigan going so heavy on the line?
Well, the obvious answer is that the Wolverines aren't at 22.5 linemen on scholarships (that is either impossible or gruesome). They're not even at 20. They won't even be at 20 after this round of recruiting. Fifteen? Nope! Based on this breakdown of the 2012 scholarship situation, Michigan looks to be at 14 scholarship linemen coming into the 2013 season. So Michigan's building the line back to where it needs to be, not overloading it.
Michigan is losing three starting linemen on a unit that, overall, was not terribly good in 2012. Ricky Barnes, Elliott Mealer and Patrick Omameh are all senior starters who will be missed, but they were hardly world-beaters. That leaves tackles Taylor Lewan and Michael Schofield as the only two returning starters on the line.
Lewan and Schofield, both seniors-to-be, are also two of the only three linemen on the entire roster who have fewer than three seasons of eligibility remaining. The last is former walk-on Joey Burzynski, who one would assume will be under scholarship in 2013 since he's a leading candidate to start at guard for the rebuilding Wolverines.
This is a young, young offensive line altogether for the Wolverines, and after graduation losses, there are only eight or nine scholarship linemen, depending on whether one counts Burzynski. One would hope he's got his way paid. Six of them were listed as freshmen last year—and of those six, four were that 2012 class we mentioned earlier who (fortunately for Michigan) all redshirted.
So while Michigan loses only three linemen this year, its overall line depth was low enough that it had to go heavy in this class. Moreover, Brady Hoke had to recruit as if Taylor Lewan was on his way out, and the fact that Lewan returned for his senior year is a major-league gift for the line as a whole. Erik Magnuson may be able to step in at left tackle in 2013—he was one of Michigan's top recruits in 2012—but like all redshirt freshmen, he's an unknown quantity while Lewan is an All-American candidate. Bit of a difference there.
Expect Michigan to go line-heavy again in the class of 2014. It may not be another five-man class, but Lewan and Schofield are definitely gone, and unless multiple walk-ons play their way into a scholarship (and there are plenty of candidates there), Michigan's going to be down in the low teens on scholarship depth again. That's not ideal.
Fortunately, if there's one thing Hoke has proven he can do already, it's recruit big-time offensive lineman prospects. We don't know if he's choosing wisely—they've all been developing as backups, and the time to prove their worth is close at hand—but he's certainly getting the guys that dozens of other schools want as well. So unless Hoke is remarkably adept at choosing the worst 4-star linemen year in and year out, expect line to be a strength long term for Michigan. Eventually.
For now, though, it's time to recruit the line like crazy, be patient and keep the fingers crossed.
*We cannot endorse this practice; instead of graduating a semester early, drawing out one's requirements over the entire senior year and bathing in the senioritis with a half-day schedule all year long is basically the greatest thing ever. Graduating early is for suckers.