So, as I understand it, a Corregidor functioned somewhat like a federal judge. However, I also read that they often acted as a mere rubber stamp for the hermandads to provide them with more legal legitimacy. I have two main questions:
Thank you and sorry if I got any of the terms wrong.
The best description is a rural magistrate. So yes a judge, but one that could investigate crimes and also rule in the first instance. They could also receive and rule upon civil cases. They are roughly equivalent to the medieval English position of sheriff. In urban areas there were alcaldes hordinarios that served as part of the cabildo and acted as courts of the first instance within their jurisdiction. There was also the alcalde mayor which was similar to the corregidor as a rural magistrate.
I can't opine on the relationship to the hermandad. My direct knowledge of these positions comes from their use in Spanish America where the hermandad was never really imposed.
The key to understanding the basic system is that there wasn't the same distinction between police and judge as in our current system. All of these rural magistrates had the power to investigate crime directly as well as to try those cases.