Consider an expert proficiency Lv80 BLM paired with Lv30 BLM in Manor. The Lv80 BLM needs to be nerfed heavily if he can still Foul and 4xFlare, or the things will die before the Lv30 BLM can even cast a second Fire II. Allowing the Lv80 BLM to maintain a complete action set without severely decreased potencies would trivialize the presence of the BLM who actually needs the dungeon to level.

So apply those nerfs. Now also consider a different party with a low proficiency Lv80 BLM paired with Lv30 BLM in Manor. If the Lv80 BLM doesn't know how to BLM, and only knows how to Fire III > Fire II > Fire II > Fire II> Transpose, he will contribute a miniscule portion of party damage while the Lv30 BLM and the tank and healer have to pick up the slack so the dungeon doesn't last twice as long as it needs to.


You cannot balance around a fully unlocked action set in a low level dungeon.

I'm willing to pump out a full Lv80 rotation no matter what level I am. But nobody can guarantee that the other people I end up matched with in lower level dungeons would be willing or able to do the same. And with the potency nerfs that are a necessary part of exemplar-ing down, it will mean that any time you end up with someone who is not as proficient as they should be for their current real level, the dungeon run will suck. At least the way things are now, people only have to be as proficient as the level they end up syncking to in the dungeon for the run to go decently.