A Shield gives this build the same or better AC than Divine Shield does I believe.
Shield AC: 3(Base for Tower) + 14 (Highest Non Arti/Relic) = 17 Artifact Shield AC: 2 (Base for Large) + 18 = 20 I suspect Relic is on par with Artifact might be a Relic Tower option that results in 21 Shield AC.
Im thinking the 52 CHA is w/ gear which means a modifier of 21 which is only +10 Shield AC. If it is not including +12 then w/ 64 CHA is it 27 Modifier for +13 Shield AC. I would guess the AC of this build to be between 122 and 125 as it looks like a normal STR build would have 124-127 AC this gives his build about +6 AC over mine.