I understand the situation as I'm working with remote/distributed teams. Our organization had been using JIRA and Confluence and when we transitioned from Trac and Basecamp to it, I was involved in preparing quick help docs and later on updating workflows. Both Jira and Confluence are easy to use.
Based on what you described, I have already in mind what information that are needed to come up with best-fit recommendations. Workflow needs to be configures, a quick guide (sort of user guide) needs to be created. Confluence is also much easier to use and have useful features that if utilized, make team/internal documentation really cool and useful. If previous documentations were already migrated to Confluence, some reformatting and reorganization of content may be needed. Then another quick guidelines or reference will be created and process flow, etc. needs to be established. For example, Programmer A implemented a third party integration and so he need to create a document, where should he put it. Should someone need to review the document, etc. Something like that. When it's not clear, Engineers hesitate and may not properly do the documentation task. Soon, remote contractors will find Confluence as good partner, questions can be asked, user mention is supported, file management and other things are intuitive.
It seems I "talk" to much but I'm hoping that there are some good insights on what I have shared.