I'll probably avoid using it entirely until I get Galuf back (someone correct me if I'm wrong on how it works when you have less than 4 party members please)!
I ask this like every year. Basically you ignore your missing party members' jobs. So when you lose Galuf for a bit, you can use his job, and when you have Galuf only, you can use any job. Barring of course any other additional rules you may be playing by.