Requiring the use of an Action to "re-equip" a disarmed weapon you have picked up from the ground with your free item interaction isn't expressly part of the D&D 5e rules, but there are a lot of "homebrew" adaptations Larian has made for the game (which is overall fantastic imho) and as long as they are consistently applied (and they seem to be), I'm here for it. That said, allowing an enemy to disarm me, pick up a legendary weapon I spent an hour solving a puzzle to acquire, and effectively make it vanish because they do not leave behind a lootable corpse is neither "realistic" or fun. I ended up just cheesing the encounter to avoid having to fight an enemy with Disarming Strike as they kept taking my best weapons. Feeling like I have to cheese an encounter to avoid unfairly and irrevocably losing something I worked to obtain feels bad. Overall, the game is great, I just wanted to leave feedback about this one specific instance of "feel bad".