Hey Steven,
Windows firewall is not being used on the vCenter server but as for the possibility of ports being blocked causing the issue we're on the same path. I've been thinking that might be happening since doing some more digging yesterday.
I'm trying to work out where in the logical network setup it could be getting blocked though, I'm unaware of any hardware firewalls blocking traffic between vCO and vCenter and can confirm there are no software based ones doing so. I'm going to see about talking with the network admins and doing some traffic monitoring to find out.
Thanks again for all the help, we should write up a manual on vCO connection troubleshooting once this is resolved haha.
~Brandit