Whether or not Justin has anything for Conor doesn't matter. If Conor wants that belt, he should have to beat contenders at Lightweight. That's what being a champ is all about. It's not about just winning that fight at the top because styles make fights, it's about proving your worth along the way. McGregor has already fought twice for the Lightweight belt without beating any contenders along the way, and he'll likely do it a third time.
Rankings aren't about who has the most chance of beating the current champ, they're about who is currently most deserving of that opportunity. That's something a lot of MMA fans forget. Maybe Struve could beat Miocic again, doesn't mean he should leap-frog right into a title fight.