Merc won't equip armor

For some reason my merc won't equip the armor in the picture below. He has 184 base strength, but the socketed griswald's

Helm gives him +20, bringing total strength to 204. The armor has a 196 strength requirement. Any idea why he won't wear it?

Strength requirement is a bit buggy and I think your merc needs the 196 flat str to be able to equip the armor

I also would advise you to give him a better armor like Treachery or Lionheart (very cheap rune words) or even

Duriel's Shell