edit: Looks like I found the solution here: viewtopic.php?f=8&t=2026&p=39004&hilit=job+requirement#p39004 (http://www.ffhacktics.com/forum/viewtopic.php?f=8&t=2026&p=39004&hilit=job+requirement#p39004)
Solution: set requirement of Job X to require level 8 Job X. How didn't I think of that one?