Well, you keep Theo because he can play CF and would still probably turn out to be a better option than Giroud if given a run of games there. So not much to do with Campbell. You keep Ox because in theory (¡attribute footballer!) he's more talented than Campbell (read: got more potential if he were to somehow show quality to go with his attributes), and Wenger will continue to convince (delude?) himself that he will turn that 'potential' into something real.
In reality, we should be selling all three of them, and replacing them with better players. As none of them are really good enough for a top club. Campbell perhaps as a squad player but it's kind of pointless for his career to stick around when the squad players should be Iwobi, Gnabry, and we should have real options like Draxler/Mahrez and Wilshere in front of them.