I know the D3 landscape very well, so a couple thoughts....the very top of D3....talking like 5-7 programs....are run like FCS programs. They look more like EIU than St Norberts. Examples are Mount Union, Whitewater, St Johns, North Central and Mary Hardin Baylor. St Thomas is one of those programs as well, and they are actually moving directly from D3 to FCS in 2021 (they just signed their first D1 class this week, also no changes in the coaching staff either). What does that mean? It means full times coaching staffs, extensive film study, extensive recruiting and not just on a local basis, installation of offensive and defensive concepts that mirror what's being done at the D1 level, deep rosters of very talented players, etc.
Tops kids at these programs typically have FCS offers or even PWO at D1's. They're not Big 10 material, don't get me wrong, but they are very talented athletes who are just an inch or two shorter or a step slower.
I have zero issues w/ LL and his Buffalo staff...football translates at any level, and what he was doing at Whitewater was very impressive. If LL can make the move from Whitewater to Buffalo, he can certainly make the move from Buffalo to Illinois.