Drake was short but was an excellent defensive rebounding team for two basic reasons: (1) they boxed out and (2) their guards got in on the action and gang rebounded. Their guards didn't just stand there at three point line watching - they got in there and helped.
They were also good on the offensive glass. IMO, that is largely a function of how many guys that go to the glass. It looks like Drake regularly sent three to the offensive glass and it paid off. Both centers collected >10% of Drake's misses, Abreu was 6.1%, Jackson was 5.8%, Combs was 6.8% and Isaia Jackson was a stunning 10%. Freshman 6'5 guard and he grabbed 10% of Drake's misses when he was on the floor.
Where I am worried is rim protection. Drake was short last season and they gave up a very high shooting percentage on 2s (54.4% I think) - poor two point defense is a recipe for disaster in the Big Ten, IMO. Gonna need rim protection and we're probably gonna need it at both C and PF.