Here’s some practical advice was a wiki editor of some years: no wiki makes sense to everyone, so you have to explain it somewhere. Where you explain, encourage the behavior you want.
Collaboration requires manual gardening, and that includes encouragement. For Discourse I encourage folks to be bold and make edits because we can always fix anything, but also it’s totally fine to discuss changes in a topic. Then, if we come up with clear edits I encourage individuals to make the actual changes.
A little bit of hand-holding goes a long way for wikae. ^_~