Darth Maul vs Plagueis

Sabers only

Maul better bite the pillow.

Even though Plagueis doesn't really like to do lightsaber duels, Tenebrous still called him a master of the art, plus Plagueis being Palpatine's master and all

So my money's on Plagueis as well

Plagueis also boasts a significant speed advantage.

I'm not sure about Plagueis being more skilled, but I do think he's above Maul as a fighter. He's stronger, faster, more durable, stronger Force connection, and so on. I think that's enough to net Plagueis the win as long as we infer him and Maul to be on a similar level of skill. Maul benefits from much more exposure, as well.

IDK

Plagueis wins every time. Even if he isn't technically more skilled, he's much faster, physically stronger, stronger in the Force, more durable, etc.

Plagueis.

I really couldnt see maul lasting all that long against him.

Maul is outclassed, mostly because Plaguies is THAT much faster.

Plagueis' speed feats don't outshine Maul's to the extent people would be suggesting, so I'm guessing you're relying on inference for Plagueis being in the same tier as Sidious?