They were supposedly Jedi who had grown "too powerful", so I can imagine they were very strong to worry Vitiate. Especially considering the incredibly strong Jedi who didn't get targeted by him. Regardless, I'm more concerned with the benefits that fighting over a thousand strong opponents would give Maul. Most fighters only engage a handful of opponents, Scourges record gives him a large advantage to draw upon. Maul has nowhere near the experience in combat that Scourge has.
Also I'm more thinking that Maul would probably get sorcery-raped in the TOR era tbh.
You can look all you want here.