No way are England's back 4 as good as they have had in years. The fullbacks maybe, but Smalling and Cahill are not even close to the likes of Terry and Ferdinand in their prime. Hart is also a massive liability. Not technically part of the back 4 of course but definitely a factor in how they perform.
I'm no fan of England but I think that there's always a tendency to overrate them compared to other sides. Realistically they never have a squad as good as the very best sides and they always seem to be tactically naive. Iceland and Italy both showed today that you can make a national side which is greater than the sum of its parts but England never seems to look like a coherent team. I wonder if it's partly the emphasis on physicality in the EPL, and also the lack of English players playing overseas and being exposed to different footballing cultures.