Not saying it was 100% just Stallions, but a month into the investigation and there is zero information any coach knew about it other than Stallions. Partridge was fired, but the report states he knew nothing about the scheme and was fired for his actions to hide evidence for Stallions.
If any other coach had been tied to it -- they would have been, bare minimum, suspended with pay. The NCAA investigation will take forever, but if this was a scheme from the top with all these coaches tied to it -- SOMETHING would come out about it.