As someone who had played every souls game. This is much more complex than souls.
That's what I initially thought too. Turns out heavy stance one-hit poking with the spear –and I assume the other weapons– and baiting attacks can get you through everything and is frequently the most effective way of dealing with those damage sponges. Like, those sword sentinels in the twilight mission. You just dodge their two-swing sword attack, attack them once or twice and repeat the process until their ridiculous HP pool is gone. Applicable to most enemies in the game, especially the bigger ones.
They're also entirely predictable, dealing with them is a matter of patience more than skill. I know every Souls enemy's pattern and yet somehow I'm outplayed by them sometimes because they react in a way I wasn't expecting. I absolutely expect everything the enemies in this game do because they seem to be programmed to repeat the same attack cycles over and over again.
I've read people saying that enemies operate on the same rules as you and praising the game for it. Only because they have a visible stamina bar it doesn't mean they are on equal ground with the player.
No, Tachibana doesn't operate on the same rules as me, he deals half my hp with one hit, has huge amounts of health, has super armor on most attacks and can break my stamina bar in one hit. Who the fuck even said this same rules bs with a straight face? This boss would be an absolute cakewalk if he had half the HP.
Gehrman and Maria don't operate on the same rules, but it certainly feels like it. It feels like a legit 1v1 duel between equals, even if they're bosses. They should've looked at these before making this poorly designed low tier fight, but I guess the "harder than Souls!! much harder, at all costs!!" philosophy forced them to come up with this crap. Even the hunter duels in BB were more satisfying 1v1s than this.