Let's say for example I create a fake Google account and I want to use my Google account anonymously on my android phone. Without using the "route all apps through Orbot" feature, What are the specific apps needed to keep that account anonymous in Orbot?
Google Play Store and location-based ones. But keep in mind: in older versions Android had an option "allow software and hardware inventarization for improving", on modern ones and on vendor-rebaked ones it is usually on by default and is not switchabe via UI. So if you need to be anonymous in using your account - use Android Open-Source Project, fine-tuned for security.