Butcher did of course do well over the long-term. I also remember him giving a real boost to a virtually relegated team to a team that almost made it.
If a slump was inevitable, why did we bring in a manager? Aren't they supposed to have ways around a slump, especially to a team that, barring docked points, would have been bottom on a quite terrible run? What's the point of bringing someone in if there's nothing he can do about it? Save the money and carry on managerless until the slump (that was fated to come) is over. Presumably that's simple destiny too and nothing to do with tactics and team selection?
That said, I am prepared to give Yogi til the end of the season (or at least the split) as there's no point calling for his head soon after being employed. I'd be delighted if he turned it around but I'm not hopeful.