Generally I don't want the wiki to grow a place to host absolutely everything remotely related to tracked music, so currently it only contains development resources relevant to the formats OpenMPT can save. I think ModLand is a great place for those documents and I don't think lack of standardization is really a problem. Documents have often been confusing but it's important to preserve those original documents, which is why often corrections have been posted (see e.g. MODFIL12 in that folder).
https://wiki.multimedia.cx/ has information on some tracked formats but it often also incomplete. In the end, nobody probably wants to convert dozens of file format documentations from one format to another in their spare time and fix all the mistakes. That's why reading other mod players' codes is often the better way to learn how to accurately play a file. I know, it's not optimal, but you can hardly blame people for not wanting to do technical documentation at such a detailed level without any compensation.