Are you sure the first meaning of バック doesn't mean "driving in reverse", like maybe backing into parking spaces? That's what I get from the context of the second panel.
Ufufu....It seems like those who are going providing back up are quite popular.
bakku can mean supporting someone, like being a backup.I know that. It's been often said that those who are good at driving are popular.Do you know, Admiral? Those who are good at being behind someone is popular.I did not. That's the first I've heard of it.The being behind someone that came up in the Admiral's mind.
bakku can also mean doggy style
