Also I feel it's important to point out that once upon a time, FFXIV had full elemental damage times. Ice/Wind/Fire/Earth, you name it, FFXIV had it.

It was ditched for a reason and it's because early raids would require you to meld elemental Materia on a fight-by-fight basis, it's stupid and everyone is almost universally glad it's been reduced to Phys/Magic/Unaspected damage types.

Speaking on where DRK and GNB currently fall in with their efficacy in raids that don't have a ton of magic damage to mitigate, yeah it feels shit. The solution is to make their magic mits work on phys damage with 50% efficacy and vice-versa for phys-only mitigations, as it allows the tanks to keep the flavour they currently have without the risk of completely undermining certain tanks based on encounter. Like in M1S where there's only one instance of magic damage for the whole encounter.