On PC I don't think it'd be hard to do, it could be set-up so that when in inventory, holding Control and clicking something sets it to the left hand, holding Alt sets it to the right hand and then Shift for dropping things. Overall I think this would make it a little easier to shift between different weapons/spells quicker and it also means it'd be easier to set-up things like switching from a sword and shield to switching the shield out for a secondary weapon rather then just switching the swords around.
Also I'd like it, if we could change the behavior of the mouse wheel from zoom in/out to switching between various load outs. Because 5~8 can become a little tricky to switch between when you are also fighting. Alternatively that hitting the mouse wheel (mouse 3) changes the behavior from zooming to load outs.