Yeah, limb positions are defined by their position on the torso.
Here is the relevant code of a normal Dummy:
Quote:
Head = Attachable
		CopyOf = Dummy Head A
		ParentOffset = Vector
			X = -1
			Y = -13
	Jetpack = AEmitter
		CopyOf = Jetpack
		ParentOffset = Vector
			X = -6
			Y = -1
	JumpTime = 4 // Secs
	FGArm = Arm
		CopyOf = Dummy Arm FG A
		ParentOffset = Vector
			X = 0
			Y = -8
	BGArm = Arm
		CopyOf = Dummy Arm BG A
		ParentOffset = Vector
			X = 4
			Y = -9
	FGLeg = Leg
		CopyOf = Dummy Leg FG A
		ParentOffset = Vector
			X = 0
			Y = 1
	BGLeg = Leg
		CopyOf = Dummy Leg BG A
		ParentOffset = Vector
			X = 2
			Y = 1
This is where all limbs are defined under where the actual actor (Torso) is defined. The text in green is what determines what the FG and BG arms are. They reference the preset names of the arms that were defined earlier in the ini. If your arms are swapped, simply switch out the PresetNames.