I think it could come back to haunt us, too.
Consider the possiblity the Devin Gardner is the Wolverine savior, and assume all the lineman red-shirt. If Gardner doesn't red-shirt then in his senior year he'll have the 3 from last year, the 1 from this year, and need 1 from next year. That doesn't seem to bad as long as everyone pans out. If Gardner does red-shirt then his 5th year will have 1 fellow 5th year and he'll need 4 younger guys to man the line.
Considering the potential importance of Gardner, and the importance of the O-line for a QB, it would be reassuring to have a few more quality OL moving through with Gardner..