Having a specific weapon doing more damage to a specific enemy is a meh ass system and basic as it comes, like the old stance system was.
Every weapon should have different values but not doing more damage to a specific enemy (it is also extremely gamey and not immersive, a katana should cut the regular guy, the lancer guy and the fast guy all the same)
It cut player freedom because every time you use the wrong weapon you are gonna feel like you are not playing optimally and making the game artificially harder for yourself, that should not be the case with any balanced game with multiple weapons.
The stance system of something like nioh\rise of ronin is they way to go if you wanna have different stances and still give freedom because there is not a correct answer, it let you decide if you wanna have longer range and more attack but slower movement or faster attacks but lower damage and range, or just using a particualr stance because you just find the moveset cool, you have zero malus for choosing a different stance.