Allow swapping between BLM/SMN mid dungeon

[Squa]

Except most dungeons also drop weapons...so yes, changing mid-raid can impact that

this would be the only good argument against this that I can see, but this can simply be resolved during forming a party if there would be any issues. Also DF currently doesn't discriminate between choose classes based on what job they are, its simple role (tank,healer,dps) so this really wouldn't change anything for DF either.

Can you give us a good reason why you should be able to?

versatility. And this is a hallmark sign that someone doesn't have an argument, when they can't give any reason other than "what about you?"