I was finding the placement of the About/Join box inside groups to be difficult for members to find if they were new to the community. So I decided to move mine above the banner box with a single line of code added to the Custom Code Bottom section. Simply add the following code and your About/Join module will move to the top on all groups.
I find that group pages with a About/Join section which shows ONLY TO NONMEMBERS is best because it disappears after they Follow the Group.
Let me know if you have any questions and if you need help with your community, by all means reach out to me. Happy to help!