I have trouble with them because they're trying to fight you with style and I am also trying to fight them with style but... yeah, don't put your weapon away in the middle of a fight maybe
like, when you Perfect Parry an enemy, you can follow up with a really strong attack, and I would always take a moment during the delay window and switch stances to whatever was effective because I thought you had to do that, and no, no you don't have to do that, just attack them when they're stunned
just walk over there and hit him