Scourge was besting the supreme leader of the Imperial Guard on Dromund Kaas - the leader that was amped by Vitiate to the point the Force flow within them allowed them to make a difference from non-Sensitives that should be just murdered by Revan's TK, into beings capable of withstanding the impact. That's how incredibly amped by the Force they were, to be resisting Revan's TK like Satele Shan-tier characters couldn't.
By obvious extension, this generic "Force flow" inherited from Vitiate, as Force flow does, amped their reflexes, strength, speed, etc. Now let's just look at the scale of that power (as above - from non-Sensitives to more Force resistant than fu*king Satele Shan) and how huge it must be for their physicals.
Basically, Yarri from that scene can be legitimately considered a Vader level combatant. Scourge still trumped her. Mara is completely beneath that level, she's in no way comparable.
Scourge stomps.