Hm...since you don't really touch end-game content, based on stat weights PLD has the lowest weight towards det (of tanks), so honestly crit would probably be best if it's on a left side piece. Right side wise if you're not trying to maximize DPS, you can slap in det where appropriate. It honestly depends on what content you're planning to do since you have to think about if you're going to be needing to DPS harder or not.
Tanking BiS meld wise is usually Crit > STR (Accessories) > Det if you can't use Crit on a piece > Skill Speed (DRK and WAR mostly.) and at the bare end Accuracy if your gear doesn't have it, though tanks are in a good spot with accuracy (especially due to weeping city body and pants if you didn't do lore ones.) If your Det is currently at or around 502+ that's fine for most non Savage content and even the baseline for A5-6S. So for the 3 tanks, crit over det largely when possible.
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