Instead of users sharing docs out of their own OneDrive, Workfront should be able to use a service account user that puts all docs of a project(s) in one central location, or better yet, use MS Teams. Both are just frontends for SharePoint, so this should not be difficult. By using a service account for a single OneDrive, or using MS Teams, all docs will be located together, you don't have to deal with uses that leave the team (or the company) and re-assign perms in SharePoint, and you have a better document history for new team members to train/ramp up.