Here's how I've always looked at this:

Theoretically, if you put the bottom 5 in a group in front of EX or Savage content - ONLY the bottom 5 - could they clear it if they played at the high end of the median percentile for their jobs and followed mechanics?

If yes, but they'd struggle and need to be in the 75th to 80th percentile? - no changes needed.

If no unless they all play 100% perfectly and not even the 80th percentile gets them through a DPS check? - they need a boost.

SE does not intend to have ONLY those jobs in content. I understand that. However, the way I see it, if you wanted to make a premade with JUST the bottom 5 DPS jobs but you cannot because the content would legit be impossible, then something is broken. Done this way, other jobs' DPS doesn't even matter. It's a test as to whether these 5 jobs have enough oomph.

In other words, top DPS isn't everything to me, but I need to be able to clear content.