Vorph
Silver Baronet of the Realm
No need for shields at all. The sword and board tree adds practically nothing to their survivability or tanking, and the amount of defense you have with a 2H is already overkill for everything in the game on the hardest difficulty. Blackwall is completely immune to damage with the proper spec, and Cassandra isn't far behind. Only used Bull when forced to, but slapping the same spec on him with a few Reaver skills worked too. The difference is damage dealt is pretty huge, and that's all that really matters. I liked Cass the best because you don't need complete immunity, and her damage dealing ability is absurd against demons and mages.Your npc list is already fairly optimal, but as said, respeccing every melee to shield tank will let you play with all of them to hear their banter.
Not sure if they fixed it but the 2H axe recipe from Black Emporium was bugged and allowed you to put mods on a weapon that clearly already had mods built in. So it did way more damage than anything else in the game because of this. If they never fixed it, I strongly advise against abusing it as it further trivializes an already easy game. (Yes, I played on Nightmare.)