Scenario one: The Fearsome Five (pre-Flashpoint) versus the Monster Hunters (616), with these specific line-ups:

Fearsome Five: Psimon, Dr. Light, Mammoth, Shimmer, Gizmo, and Baroness Blitzkrieg. (No, the Baroness was never a member of the Fearsome Five, I just added her for fun)

Monster Hunters: Ulysses Bloodstone, Makkari, Dr. Druid, Fat Cobra, Zawadi, and Namora. (Treat all of them as still alive, since death doesn't mean much anyway in the 616 area code.)

Scenario two: same as scenario one, minus the speedsters Blitzkrieg and Makkari.