We can't have gone from a team that has won 6 titles in 7 seasons to a team that has been "badly coached" by the same group of coaches. What exactly do you think has changed? You simply cannot expect the same results when the team has been decimated with injuries even before a ball was kicked, Bobb being the first "victim". It's not just the players out, it has a knock on effect with players not being ready for 90 minutes every week (they wouldn't be second or third choice if they were, constantly having to change the team play players who are not fully fit or need resting themselves and expect the same results as in previous seasons.
If you look at the "Goals For" column, only Liverpool have scored more so clearly the biggest issue is we're conceding too many, and it's no coincidence that the key problems have been midfield back to defence. Everything else plays are part of course, you're bound to have things not go your way in a certain number of matches no matter what but the defensive issues are the key. I bet we have been able to play the same back four more than once or twice.