One of the programmers on our team has published a snippet of code that allows you to switch between 2+ cameras on the robot while using minimal bandwith. The snippet of code can be viewed in this thread.
Our roborio just couldn’t handle two simultaneous usb cameras even when not running the robot it just errored out. We ended up with a USB camera and an Axis IP Camera. This gave us a 180 degree view and a nice aim camera.