First, I will note that I volunteered to be an admin on the classic wow guild’s discord because of the amazing service and job they had done providing service to the classic community, and thus, have some bias on this issue. However, I was not part of the creation of any realm discord or the conflict that has since arisen.
The CWG team, to my knowledge, is/was not opposed to merging into your server or incorporating you into the leadership of the cwg server, but the talks have not been fruitful.
The CWG team does not have any more of a vested interest in seeing their server succeed over your server, than you obviously do in the inverse.
CWG set servers up for every realm and then passed leadership over to established leaders from each community as known through the months of seeing leadership interact on the CWG server. The CWG’s team interest is in the community and their past efforts have demonstrated competence, dedication, and objectivity in maintaining the CWG Server
In the short time since launch, your community has grown through your aggressive efforts at publicizing your discord (good job). Unfortunately, while I would otherwise have nothing but praise for your efforts, there were multiple occasions of unwarranted brigading being directed towards the other discord when it was advertised or mentioned. On the CWG originated discord there has been much discussion of the toxicity of the “other discord” but I have not observed that toxicity and the moderator team of Mannie’s discord were respectful in my interactions with them.
As a Guildleader, I’d prefer one main server to minimize/concentrate effort, and my vote would be for the known quantity of the CWG established discord due to their proven track record as well as my experience with the team, but I know from reading on both discords that neither discord pleases the entirety of the community.
For the OP, I’m not sure if there is a straightforward or easy solution to the emergence of multiple discord servers per realm but I don’t believe that simply choosing the largest server is ideal.
Honestly, I think the best solution would be to advertise both discords until the server launch hype fades and the communities establish themselves.
Either way, great job on your website!