We needed to sign players last summer with more Premier League experience. Trezeguet, El Ghazi, Guilbert, Konsa, Hause, Luiz, Nakamba, Wesley, Davis, Samatta, Hourihane, Jota, McGinn all had no PL experience and are mostly either pretty young or new to the country, or both.
Most of them have played lots of games this season so it is hardly any wonder we are where we are. It's OK having inexperience if you are a very decent player but we averaged circa £10m signings and these days it's peanuts.
Whoever made the decision to go with inexperience, they are the ones to blame for our plight.
We should have tried to bring Cahill back to add experience to the defence. We should have signed more experienced CM's and at least one striker who knew the league well.