Great idea! I can try to set up a discord channel.
The first thing everyone can do in the case of "alerting each other" is turning notification for steemit on. So you get notified if someone comments on your stuff.
This post can help you:
https://steemit.com/steemit/@scrooger/steemit-notifications-where-or-how-or-why
Although discord would be good it would be great if we could find a way to as a core thing communicate directly via steemit as it keeps our communications really open and it will attract new people to join as they will see the activity very openly :-) What you think of the tag idea? Or is there any other way to create groups on steemit?