Yeh, I appreciate that is what they're for, but if you have 100 different networks, being able to restrict a couple of networks is a lot easier and quicker, and easier to manage, than giving access to 98 networks
Have you considered managing your admins via a script? There's a manage admins script that you can use to modify permissions on orgs. It'd be easy to modify it to change perms on just the handful of orgs you mean.
It's what I use to manage permissions across 70-odd organizations.
An alternative would be to move your cameras to a separate Org and keep your 'networking' networks separate in the original org. Then your Org admins in teh main org could be given granular network admin access in your camera org.