As far as the "Power Grip" idea goes I think its a good idea to implement not only because "it saves assets" but it can also be applied to the duel wield mechanic. Just like the concept image the blade can have two states. The shorter duel wield mode and the "Power Grip" (extended) mode. This could be a simple crafting recipe of just the blade. so a player would have four swords on them at any given time to give themselves diversity in combat. two short swords for duel wield, the long sword, and another stand alone short sword. the fact that you need a crafting recipe and not a hotkey will make it so you have to plan before your fight and also make it easy to program the difference between duel wield, power grip and one handed.
The duel wield recipe can be two short swords that then turn into a single duel wield item.
I'm new to the forums and this game so sorry for my sloppy format. I hope my idea wasn't redundant and was at least a little helpful.