In this football crazy state it doesn't surprise me. Sure they are the big name, but Ohio State would recruit well just about in any state given it's history, traditions and the on-field performance each and every year.
Michigan does just fine for itself as well as the Florida schools.
OSU is so successful because it gets first choice of its kids AND the very best in the other Big Ten states with losing programs. What kid in Illinois is going to go with UoI if OSU offers him a scholarship? There are no programs which would be more appealing than that at OSU only a handful is its equal.
I looked at the state origin of the starters last night and there were several more out of state kids on UM (including from Ohio) than OSU.