How we determine balance and its flaws.

[Vendalwind]

So... You basically want StB balance back? Where every raid was Bard + Dragoon + Ninja + [Selfish DPS] (Or often, SMN because they did pDPS equivalent to that of selfish DPS but also had utility and rDPS boosts too... Like they still do!)

No.

The "Ideal" scenario is where any 4 jobs can be used together and be close enough to not matter in terms of DPS.

Yes, but with caveats being that proper group diverse composition yields some rewards and having all roles also yields rewards. Last patch for example if not for the role bonuses and duplicate class reductions a team of 4 SMNS probs would have been the best and safest to play in any fight. Thats unhealthy. A meta will always exist. but the nature of the meta and the balance as i suggest above will yield your ideal scenario most effectively.

You assumed much beyond the scope of my post. I spoke of maximized dps. not viability.