Currently, you get more tomes(soldiery) for the low level daily roulette, as you would get from a expert or high level dungeon run (not roulette).
So, to be tome-efficient without a "dungeon static"(lol), it kind of is mandatory to do it.

I always tank low level roulette and when I spot a not synced player I will pull each and every mob this dungeon has to offer.
Naturally I don't feel the impact of rushing tanks in low level roulette so I would not like to see the "clear = x; done not clear: x/2"-thing to still be able to decide myself if it's worth pulling every enemy in the dungeon - wouldn't wanna do that with all synched 50s.