Recently, we noticed in our of our BOL groups that even though several individuals were given the role of creator and coordinator using the Admin tool, they did not have access to the member page where they could make changes. The original Group Manager could, but not the additional people given those roles. Our best guess is, and through testing, that it appears you only have one shot at naming 'group managers' at the initial group creation stage and that the role of creator and coordinator are different than group manager. The original person is no longer employed at Oracle, so can't be 100% certain that is what happened.
Can someone confirm whether this is the expected behavior for BOL groups?
Got my answer from someone offline - you can add additional group managers from the Create Group/Add New Members tool by clicking on the group name and adding another email address to the 'group manager email' field. That's the only way another member can have access to make group member edits.