L&E Dwarven Vault ACs

I had a question about the ACs of the dwarves living in the vault found in the dwarf entry of Lairs & Encounters.

I think I'm also confused on the explanation of the weapon and shield fighting style proficiency in the core ACKS book, especially where it says "Bonuses are in addition to the standard bonuses for fighting in the given manner. For instance, a character with weapon and shield fighting style proficiency gains a total improvement to his AC of 2 points." So they get +1 for having this proficiency when using a weapon and shield, but how do they get plus two?

Here's my AC breakdown of the dwarves listed (correct me anywhere I'm wrong please):

Dwarven Warden AC 7 (plate armor (6), shield (1) this seems correct)

Hurgon AC 8 (Dwarf-forged plate +1 (6+1=7), Shield +1 (1+1=2), Fighting Style Weapon and Shield (1)) by my calculations, shouldn't Hurgon's AC be 10?

Dwarven Defenders AC 8 (equipment not listed, but maybe they have plate +1 (7) and a regular shield (1)?)

Torrad AC 9 (Dwarf forged plate armor +1 (6+1=7). Fighting Style Weapon and Shield (1). So AC 8 as listed. Though he's missing a shield. So he must have one for the proficiency bonus to work. So maybe that's the missing point.

Torrad's entry also says: "(AC 9 instead of 8)." Not sure what this is meant to convey. He's got more AC? Again, is something about the armor, proficiency, or missing a shield or something? Not sure.

Bhurador AC 12 (meteorite iron plate armor +2 (6+2=8) and shield +2 (1+2=3), Fighting Style (weapon & shield) (1), so 8+3+1= 12 total, that looks correct?)

Thanks for the help.