The core feeling of clunky-ness comes from the fact that no other tank is as forcefully dependent on their gauge more than GNB.
PLDs core burst comes from Fight or Flight and Requiscat, which are cooldown based, you can argue MP cost but Requiscat will still execute. WARs core burst comes from Inner Relase + Primal Rend and Inner Chaos, again cooldown based. DRKs comes from Delirium, Shadowbringers, Living Shadow, and Bloodweapon, all cooldowns. Living Shadow needs gauge, but only half of their gauge, every 2min, and Bloodweapon being every 1min ensures you'll have it.(unless I accident missed something from these three tanks)
Now look at GNB, who has to have a full three cartridge gauge, every 1min, to execute the core of their burst or their whole rotation is ruined. Only one way to get that gauge quickly through Bloodfest, but that only aligns every other burst.
This isn't a "skill issue" imo as rather a slight design flaw as it makes unnecessarily restrictive. Can't use my cartridges on a dungeon mob pack right before a boss or I will be waiting the 9gcds to be able to burst unless Bloodfest is there. Can't help burn an add phase faster because I need my cartridges to not be heavily misaligned with raid buffs. Shadowbringers GNB could though, as even if you spent all your gauge, getting three GCDs in for the bare minimum was feasible and not bothersome in its gameplay.
Changes to the maximum number of cartridges, or bloodfest, or Double Down, or adding any other affect to GNBs to alleviate this is needed. Just have to see if we get any changes in the future.
