Seriously? Just look at Jose’s defensive record over the years and let’s have that conversation again
Carvalho played 7 seasons at Chelsea, he also inherited Terry and the rest were brought as backup for less than 10m each. Paulo Fereira was also pretty useful signing, not to mention Ashley Cole and Belletti for 3-4m was it?
Next is Lucio who was absolute rock and vital for Inter in that treble year.
Zouma is the only "high profile" signing you can call it a failure over the years. You can't seriously compare Toby type of signing to bringing up some odd backup at 2-3m. It's like saying Fergie had a poor transfer record due to bringing guys like Dong and Ljajic, Tosic, etc..