Are you saying that 33% is no big deal?
Mind you, a P2W Eidolon is about 25% more damage (which you were running two of). If 33% doesn't really matter, why use those?
Another perspective:
If you have 140% Assault (about what I have on my Grids, at 100% HP), you'll need to to reach 186% for a 33% increase in damage. Considering how FLBs are 5% more Assault, that'd require NINE more FLBs into that Grid. Which just isn't physically possible, since you're not realistically reaching 140% Assault without any FLBs from your Grid.
The whole point was, it's not just so casually easy to one-shot Jack. You, for example, are running your own Hraes and a gimmick Hime (Aether) and still barely managed it. Sure, debuffs would've made it noticeably easier. But not everyone is going to have their 100% Eidolon (unless they rerolled into one) or even a gimmick Hime (Aether, Uriel, Tyr I guess, the list goes on).