NIN's less formulaic than DRG rotation wise but it's not much harder and is a form of a rotation, just much less obvious at first glance whereas looking at DRG's rotation the loop/pattern is distinct as soon as you see it.

(opener of DE > SF > M) > 123 > DE > SF > 123 > DE > M > SF > 123 > DE > SF > 123 > M > DE > SF > 123 > DE > stuff

Not hard to do as you see it but not such an H > X/Z > P > X/Z > H > X/Z > P system as DRG, especially with how slow Mudras can come out and turn a 123 into a DE combo based on time.