PTMP using subscriber for backhaul/uplink

What is the downfall for using a subscriber in a PTMP network as the main backhaul? What would I be loosing in bandwidth?
I’m planning a surveillance camera project installed at a single location (8 cameras) as a pilot project. With the potential to add 3+ locations if the pilot works, all camera locations have LOS and are under 800 meters in distance away so I’m not worried about that. There is no LOS or NLOS view from the NVR (network video recorder) location to the camera location but I can do a hop on a roof to make it work.
What I am thinking is installing an A5-15 on the first camera location with the plan of the 3+ other locations being added as clients to the first one.
I am limited for space on the camera locations because they are traffic light masts and I only want to be at the first location once, that is why I’m wondering how this would work out.

This is what I was thinking, with most of the traffic going towards the NVR:
A5-14 ----> C5----B5-Lite -----> B5-Lite----NVR

Thanks for the input!

EDIT: add diagram