What people above have said, go buckler / round shield and actually parry the attack rather than block. Generally you need to upgrade the shield to the metal in that zone before you can parry the harder hitting mobs in the zone. e.g. Trolls will hit through and stagger you if you try parry with a wood shield but Bronze is OK. A 2 star Draugher or Abomination will similarly stagger you on a bronze shield but are are easily parried with iron

The concept of tank isn't really a thing. Most things you parry will die on your counter attack, it isn't as if you stand there for 10 swings soaking damage. Bows are useless on most bosses and take a long time to kill anything in the worldso basically useless apart from 1 mob in the mountains .

Both of you on Ategirs would be better, don't have to bother with shield then and just dodge, hack n slash your way through the game, it's more fun.