@Gentleman Jim
You didn't say your coaching sometimes improves excellent defenders, you stated he would improve with the coaching you offer.
Not that it matters but it somehow matter enough for you?
I don't even think your defenders have even improved that much. Walker was excellent before and still is.
Otamendi was one of the best defenders in La Liga
Stones is still a mess.
Your coaching seems to be buying the biggest name thats available, if Umtiti (sp) didn't turn you down then this thread wouldn't even exist.
It is lazy if we're honest. Lazy enough to go all out for Alves last summer or even approach VVD.
Clubs simply do not need to spend the sums you do on defenders to have a fantastic backline.