His record is terrible, no one speaks about him as a good coach, just that he is a good motivator and tough.
His best season is the season he had the least amount of time to influence the team, that is likely the biggest red flag I see, it is similar to Lou in New York, the team got worse the longer he had his influence over them (obviously a GM and coach are different and it is not a 1 to 1 comparison).
I won't pretend I know the styles of every coach, but watching St Loius under him I wasn't impressed.
Not like I watched a ton though, nor was I paying attention to systems, that is why I am not sure.