The "rule" was changed, if you will, quite a while ago. It's "suggested" by the NCAA those 'rules' are followed. But, roster sizes have had their say when a team could suit up more than 99. Then 0 came back in...
As as understand this it's more important to let the official know if there's a tackle eligible situation than to tell them 87 (in this case a guy like Lewis) is in a tackle role.
OFF the top of my head:
All the starting OL are in the 70's. In the two's, I think VanDeMark is 56.
Skills are single digits.
TE's are 80's.
QB's are in the teens (there's a #10.)
RB's are single digit and 20's.
Pretty traditional roster overall ...