Just because both Hill and Cox struggled at the club with the current owner, doesn’t mean Cox wasn’t doing a bad job. One may also speculate how bad things were before Hill came in after Cox in charge for a considerable length of time, perhaps leaving Hill with an impossible task under pressing circumstances. That’s not to say Hill isn’t doing a bad job either.
I would argue that Hill’s struggles are putting Cox’s into more context. He may not have been great but possibly not as bad as we thought at the time?