As I understand it, there are NCAA limits on the official coaching staff (head coach plus two assistants as @VTScoop says). I expect that there probably aren't official limits on other support staff -- think Alabama's army of football "analysts". But whoever you hire has to fit in your budget. Also, school-paid support staff are likely limited on what amount of "coaching" they are able to do.

I'm including a link to a FloWrestling article on the topic from 2017 based on released tax records. Their RTC had more than $5M in the bank, which they can use to pay for training opportunities for members and hire top talent as RTC staff (like Ty Walz and James Green in SERTC). That can make a big difference overall.

That 2015 return for PSU is quite interesting -- it shows $5.7M in income in the prior year (2014) and only $372K in 2015. So maybe they got some crazy-large donation in 2014.

In any event, that same article has tax returns for many RTCs including SERTC. Our 2016 showed gross income of $330K, which was a big bump compared to $55K in 2015. But at the time the article was published, nobody had anywhere close to the amount of money in the bank as PSU.
[Post edited by nvpbrown at 03/21/2022 8:35PM]