cake’s default mode of per host/per flow fairness would be simplest. If you are natting at the router that would be
cake nat diffserv4 on both up and down.
You are going to run into severe bandwidth limitations however with that many users on the link, and it might behoove you to add some
diffserv prioritization to flows you care about like videoconferencing. I don’t honestly know how to do that in mikrotik.
The paper and man page on how cake works might be of help:
https://man7.org/linux/man-pages/man8/tc-cake.8.html
https://arxiv.org/abs/1804.07617
There is also a very long thread on these forums about the options in cake, here: http://forum.mikrotik.com/t/some-quick-comments-on-configuring-cake/152505/249