Someone Explain This To Me

The enemy had 6 berserkers, all positioned at the back, with a singed at the back right. My noc jumped to the singed, and both the guy's olaf and volibear turned around and instantly stunned him without jumping to the nearest unit. Not only did this happen, BUT HE WAS ALSO STUNNED THE ENTIRE TIME WITH 2 GLACIALS WITHOUT EVEN OLAF ULT. How does this make sense that they didn't jump to my front line units? I feel like this game is extra pepega if the units don't even do what they're supposed to, plus the stupid rng!