I wish it was only a Pair. There are at least 4 dedicated Discords for Dominions. Each relatively active.
The break down is partial because of modding rules. The one I frequent is relatively strict, but it’s also about getting a responses.
There are only X number of channels to have discussions, and if one is being used, then it’s harder to start a new discussion on that channel until the other discussion natural ends. Or go to a different discord. That’s why each of the discords I know about have a question and answer channel and a General Chat.
On a forum, each new discussion gets its own thread, making it easier to scale.
I think one of the biggest failures of Dominions, and the reason for the fragmentation is mostly a failure of Illwinter. The use of Steam as their main platform for their forum drives people to seek help or community almost any where else. The software is awful.
I think Discord helped fill in that void.