Autodiscover across multiple GMS 2.0.1 servers

I am currently struggling to get autodiscover to work across our 4 GMS 2.0.1 servers, one for staff and 3 for students.
Everyones email address has the format

I have SRV DNS records setup as follows.

Record Key Type Value
_autodiscover._tcp SRV 0 0 443
_autodiscover._tcp SRV 0 0 443
_autodiscover._tcp SRV 0 0 443
_autodiscover._tcp SRV 0 0 443
_ngms._tcp.datasyncstf SRV 0 0 443
_ngms._tcp.datasyncstud1 SRV 0 0 443
_ngms._tcp.datasyncstud2 SRV 0 0 443
_ngms._tcp.datasyncstud3 SRV 0 0 443

All the servers referenced there also have A records correctly setup.
Using I have determined if I only have an autodiscover record for 1 GMS server and use the credentials for a user on that server in the Connectivity Analyzer, it works fine.
So my setup is ok connectivity wise, firewalls etc must be setup right but how do I setup DNS to make this work with multiple GMS servers. Using one is not an option as we have over 3000 users, using a different domain name for each server is also not an option as it will cause massive confusion, ie.
The documentation here seems rather vague in the multiple server config part.

Anyone have any ideas?