Round 1: Maul can defeat three low level inquisitors, as seen in his showings on Malachor though it would be a decent fight. Maul wins 9/10
Round 2: I just do not see Maul taking down three low level inquisitors and the rather competent Grand Inquisitor, who is quite the smart and calculating fighter, all by himself. Still, it would be rather close fight with Maul taking one or two of the lower inquisitors with him. Team wins 7/10
I am not entirerly sure though.
Old Master Maul wasn't that much ahead of those three inquisitors. Well, not even sure indeed was ahead. He has shown, that he's superior to any one of them, but for me, they were slowly overhelming him. Plus, when Ezra and Maul opened that doors, Ashoka and Kanan already fought those three inquisitors. And they didn't beat them. At that point, Ashoka was already Maul's equal.
R1: split or very small advantage to team
R2: perhaps, with an huge ammount of luck, Maul would be able to take 1 out of 10.
Anyway I believe that TCW/SoD Maul would take a solid majority over those three. Not sure about R2 anyway.