In the end, I think the thread is telling you, you dont need to be using Gladiator in the Dungeon, you can use Paladin fine, and that you can use Jobs for everything, and never use classes again.

If not, then the whole thread has missed the point or doesnt do dungeons but I watch Doctor Mogs stream and they all use Jobs and never switch to Classes, so maybe you need to tweak your strategy Mr OP?