Tyranus would get pawned. Grievous is a trained Jedi killed who fights with 4 sabers. He alone would make Tyranus sweat. In Labrinth of Evil it says sometimes when Tyranus and Grievous duel Tyranus has difficulty defeating Grievous. Asajj and Durge are about equally powerful and Tyranus is quite a bit more powerful than Asajj, buit I'd say the two toegther are even stronger than grievous, so they'd won Tyranus. The 3 of them together would beat anyone.