Benefits will change based on the exercises you use.
I like pairing two different muscle groups for accessory work because it saves time and helps with conditioning. I know I'm out of shape when a simple tricep/bicep superset gets me nauseous.....
You can do different movements for the same muscle group to increase substrate defecit. For instance, if you reach absolute failure on a bench press, by defenition you cannot perform any more reps. But if you immediately go to a cable flye right after, you can extend the set longer and provide a greater systemic stress.
This also applies to 'pre-fatigue' (i.e. isolation move before compound move). Try doing leg extensions before a set of squats and see how fried your legs get.