Thanks for the feedback and compliment. We want our videos to be relevant. We will have feedback mechanisms for the viewers to tell us. Also we have up front subject matter expert review from Epic to make sure the content is relevant before its even made. That said, everyone learns differently, so we want the content to be correct and well presented and produced. You may see occasional over lap and repetition, but this is by design. Once older material loses its relevance, we will keep it up (because many teams still on older versions) but we will try to categorize it as such.
As for contributors, those are the Authors that create the material. We want to work with best instructors who also have vast engine experience. Not just anyone can contribute because we have a well defined quality standard. That said, anyone can submit a proposal to create content for us. There is an author selection and vetting process.