I really need to know why some enemies have infinite fucking poise. (and other gripes)

I'm someone who never plays PvP, but I'm not sure I'm remembering things wrong, but I swear there are some enemies in the small/medium size category that have no business shrugging off a Fume UGS or a greatarrow to the face, sanctuary guardians are egregiously guilty of this, shoot one right in the face with a greatarrow and you might see it twitch a little bit but not even move.

A couple of enemies in the Ivory king DLC also have infinite poise (or at least it felt like it) no matter what you hit them with, but the worst are the frozen fucking reindeer, they almost always feel like they hit you no matter how precise you roll and come in packs of 2 or more if you can't kill one fast enough

This is made even worse by the fact that poise either doesn't work or it's different now. I know that people are going to say that I'm stupid for trying to trade hits, but if I'm wearing the armor of someone known as "the rock" I expect to be able to take some hits before flinching.

Now the game just feels like a game of how fast and long you can swing your weapon, because poise would be very fucking helpful in the shrine of homing soul arrow, it also feels like a game of how fast you can find the cheese, shoot the magic spammers in the back and hope the archdrakes don't stunlock you to death with their very quick three-hit combo from two or three sources because there's always more than one enemy attacking you at once.

That brings up a giant source of frustration for me... there are a lot of encounters against two or more enemies at once with one always spamming ranged attacks in the back. I know the first game had about the same kind of scenarios, but in that game you had poise, if you had heavy armor you could tank a hit before swinging and doing damage to the three enemies about to swing at you.

One last thing before I go: why does estus healing suck so bad in this game? in DkS1 your character used it with some fucking urgency: whip it out, take a swig, put it back, and it could heal more than a quarter of your health bar, in dark souls 2 it feels like it's meant to be used in between battles because your character takes it out like they had a bad day and are gonna enjoy this big gulp of estus, but they can't because they got killed before they could get it out of their damn pocket. I dunno, maybe the second game isn't for whiners like me.