I don't have a 1-30 ranking, but I'd grade him as "pretty good". He isn't perfect, I do think you *can* upgrade on him, but that most moves would be "lateral". Much of what people piss and moan about Hoyer can be said about others. And for his drawbacks, he rarely just sinks the Cubs or that they're watchable.
The Brewers are good, yes. Good reminder, though, David Sterns and Craig Counsell were considered the engine, both left and the Brewers have been just fine with both Sterns and Counsell haven't had the same success. So when we do these things, what we attribute to one person or another isn't always the case.