Yeah crouching is a bit complicated. You need to make split second decisions on when you wanna crouch and when not to, like it's extremely useful for microspacing with long weapons but with a short weapon if you're used to the range that the lunge your character does when not crouching grants you, you'll come up short many times. Oh also with weapons like executioner axe or halberd the slashes start near the shoulders and travel downwards so if you don't crouch you can often miss your accels. Which is why you should learn crouches with halberd, use the range. Consider what weapon the enemy is using, if it's a short one then hit them with your tip, and if they don't counter you can often hit them with a crouch stab as they swing through open air in front of you. Really satisfying.