Disarming dramas (or am I just a sword loser?)

Here is my observation:

The Core Rulebook does not contain any generic rules for disarming opponents (generic in the sense that any character could attempt it). The Heroic Disarm knack, the bull whip weapon and the Nightgaunt's Trident attack all permit disarming which means the concept of disarming exists in Arkham Horror.

Now you could just say, "You want to disarm that cultist? Sure, go ahead and perform a complex action using whatever seems appropriate, probably Melee Combat. Did you succeed? Great, the cultist's wavy-bladed dagger goes spinning across the floor." But then the player with Heroic Disarm says, "Wait, other characters only need one success to disarm? Why did I take this knack then?"

I feel like this is another case where Edge Studios creates confusion by presenting specific solutions to a problem for which there are no other rules (cf. my post on difficult terrain).

Here is my house rule approach to disarming:

• A character can attempt to disarm an opponent they are engaged with by performing a very difficult complex action using Athletics or Melee Combat.

• If successful, the opponent drops one item they are carrying.

• The character performing the disarm chooses the item the opponent drops.

• The enemy does not suffer any damage or injuries from this action.

• The enemy can perform a reaction using Agility or Melee Combat to avoiding dropping the item.

• At the GM's discretion, disarm will not work against certain opponents or items (i.e., you cannot force an Elder Thing to drop its tentacles; you cannot knock off the Mi-Go lightning gun that has been surgically grafted onto the poor victim of Yuggothian experimentation).

Here is my rationale:

• The Nightgaunt's Trident attack provides the basic template for a disarm (i.e., requires three successes) but their way of doing it is still unique since they get to do damage and an injury as well as disarming the opponent. Any other character can attempt a disarm but they trade away the chance to do damage (otherwise, you would always try to disarm your opponent when attacking them).
• Making this very difficult provides niche protection for the character who has taken Heroic Disarm (they have to use Athletics to disarm this way but they succeed on two success and get a bonus for three successes). Indeed, the wording of Heroic Disarm requires a disarm to succeed on three successes otherwise Heroic Disarm would be pointless.
• Using a bullwhip to disarm requires three successes but is still distinctly different since it must be done with Melee Combat but allows a disarm at range and also does a bit of damage.