F2 Select order confusion

This also applies on Co-op missions.
So, here I am with Dehaka and his army of mutalisks. Dehaka and Mutalisks are on opposite side of each other.
I F2 select it and and Dehaka’s face comes up. I click the portrait but the screen focuses on Mutalisks instead.

Why doesn’t the screen focus on the primary unit? Dehaka was clearly the on that came first so why doesnt the screen focus on him?

Is this something the keyboard shortcut settings???