This only proves my point.
Ironically, you seem to be missing mine.
Terra (someone who was confirmed weaker than Xehanort)
He beat MX once, then created the Lingering Will to beat MX (as Terranort) again.
was able to beat an angered Eraqus that fully intended to kill him.
An angered Eraqus who nevertheless retained visible reluctance.
And that "pepper spray" very clearly stopped Eraqus in his tracks to point where Xehanort, who had re-approached him, was able to easily walk away without any further resistance.
E.g., even a professional fighter can be incapacitated by a random street-punk with a concealed weapon.
That didn't prove MX was more powerful; just more pragmatic and ruthless.
Lastly Eraqus himself admitted he couldn't stop him.
Again, only because he was blindsided by a cheap shot -- one that MX was visibly waiting for a chance to use during the entire conversation.
Bottom line: Eraqus was limited by the Idiot Ball trope, not actual power.