OCTO to split the work between videobridges

Hi all,

I was watching this video which explain the reason behind OCTO.

at 2:42 https://youtu.be/32CpoFGKHM8?t=162, does the load split 3:1 between the the two video bridge?
dose the OCTO connection count as one user or it will act as 3 users when it reach the AU VB?

If this is the case (where you can split the work of one conference between multiple VB) can I use that even if the VB in the same location, and using this method to split the load between multiple VB?