Honestly this is one reason I'm hoping that Kelly ends up being co-defensive coordinator. Clearly there were some issues, and while I think most the blame lies with Tosh (not necessarily his fault, from what I read even he wasn't sure he was ready to do it), it's hard to say Golding performed his job perfectly either.
I know a lot of people don't like the job he did, but Charles Kelly was by himself as defensive coordinator for three straight top 20 defenses, in a power 5 conference. Even if he's not the one doing everything, I'd think he'd be plenty capable of providing what was missing (he was also linebackers coach at Florida St.). I think it's a little naive to assume you just remove Tosh and Golding becomes a lot better. Golding was defensive coordinator in the C-USA for a couple of years, he's young, and he's still learning on the job...