Additional information:

When switching from a non-dual wield bar to a dual wield bar, the dual wield idle animation is replaced by the idle animation for whatever bar you swapped from. The weapons are positioned correctly in the character's hand and other animations, such as side to side movement, are correct.

There is, additionally, no animation for switching to a dual wield bar. This is most noticeable when switching between two dual wield bars.

It also seems to me that the dual wield idle animation--visible by sheathing and drawing the weapons--is not quite right; it seems different even from the combat memory reduction changes.