Out of the comfort zone! Dev Challenge.

[Kjara]

Revive Monstrosity. That will do it :/

[Jin_Uzuki]

Tbh, I feel like what OP is asking is already in the game.

FFXI game system already allows tons of improbable and different strategies, or weird job/sub job combination. Of course, most people want to play it safe, but nothing wrong with it either.

[Nyarlko]

On the off chance that the devs actually listened to your suggestion and implemented something like this, do you really believe there is even the slightest probability that they would actually play it themselves to examine anything, much less "balance" issues? How would forcing jobs into unconventional roles help determine any sort of balance issues to begin with? Do we really need mage melee, bard tanking, or the like to be looked at? Do you really want to have to collect yet more gearsets to clog up your inventory with just for the sake of being able to do them?

There is not really a need or widespread demand for what you are asking for, and the "dev challenges" that have been implemented (Master Trials) seem to be rejected by at least most of the non-Japanese playerbase already. What little dev manhours that can be mustered should be used towards fixing our most common complaints rather than building new systems from scratch for fringe style gameplay.