Onimi and Simrra vs. Darth Plagueis

I say Onimi and Shimrra prosper.

Onimi solos.

Shimrra may very well solo; I would call Plagueis somewhat better as a combatant, but Plagueis is gonna see amphistaff for the first time in his life, fight somebody against whom he can't use Force Sense, has 0 precog info, can't use Force offensively; Lightning kinda helps even the odds, but still Shimrra has too many trumpcards.

Team together wins easily.

Plagueis's midichlorian manipulation may allow him to deal with Onimi's toxins, but he'd be hard pressed to deal with both of them without having any experience fighting Vong.