Simpler to just have an option in the party window to fill any roles the group is missing for whatever run you are in. Only lights up if you have the proper weapon in you inventory as well as the needed class leveled to that dungeons minimum, also the job crystal in Sch's case. Once you click it it brings up a list of the weapons you have that match that class/job for you to pick from. If you have the job crystal for your chosen class it would automatically be equipped as well. Once someone switches it grays out the option for the rest of the party unless you are missing two DPS or the like. Would be a pain to set up for SE but I find it best to make it as simple as possible for folks in DF. Or you could just register gear sets beforehand so that the game just equips that instead of a complicated inventory search.

Sorry to ramble, thanks for your time ^^