One part of RMU disarm I don't understand:
"The defending foe makes a defense roll... as if it were an attack roll (subtracting any parry used)"
Which means a full parry[1] is the worst thing you can do if someone is trying to disarm you. So even the most skilled swordsman can be disarmed as easily as the angry peasant with a club if they happen to parry.
As an aside; the example mentions the peasants skill; but does not mention if the peasant is parrying.
Edit: I added a bit more of the original text to make my comment actually make sense.
[1] Which I generally understand involves keeping your distance, and using your weapon to keep your foe at bay.