Sometimes ?
Bueno Hombre
This is not about just "knowledge", that's more suited to math instructors.. Experience, expertise and the ability to "impart" those qualities NOT just "book knowledge is what they should be looking for re instructors.
Seems BH (and CX generally) are ok with the destruction of a meritocracy in lieu of "qualified" and known trained professional instructors... Cheap, cheap, cheap..........