I just want to see a sensible solution applied from the start, e.g.
  1. Have all skills usable on their own, with natural but nuanced combos between them, rather than all but 1-3 weaponskills being bloat in any given GCD (outside of Perfect Balance). This may benefit further from dynamic animations to better fit the animation flows of their prior skills, and/or dynamic effects. Slightly trimming the total number of skills might also help, given that you would then already have more animations and capacities than you would buttons.

  2. Have all combos be precise combo lines. Fill in redundant abilities, such as True Thrust being present in multiple combo lines, with unique variants (i.e. returning Impulse Drive). Heavy Slash, Fast Blade, Hard Slash, etc., all gain new partner skills to fill out their alternate combo uniquely, and each of these tanks could again support a full second combo. For instance, Heavy -> Skull -> Butcher; Maim -> Path -> Eye. Only 2 keys required.

  3. Have all combos branch geometrically, so that each GCD has an equal number of choices. A warrior, for instance, would have access to Heavy Slash and Maim initially. Heavy Slash would give access to Skull Sunder and Rive, while Skull Sunder would give access to Butcher's Block and Breaker, Rive would give access to Undertow and Storm's Wake. On the other end, Maim would grant Storm's Edge and Brandish, and Storm's Edge would grant Storm's Eye and Storm's Path and Brandish would grant Mythril Tempest and Sea's End. 14 skills. 2 buttons used.