Southgate is an idiot.
Are there English Centre Backs that are better passes of the ball then Chris Smalling? Of course. Are any of the English centre backs the second coming of Franco Baresi? Feck no... so to rule out Smalling on that basis is daft.
Not only that, but there are times in games where you just need to see the game out, and throwing on your big tall centre back who can head/defend better then most English CB's is clearly a great option to have - why rule that out?
Oh yeah, I know why, because Southgate is a feckin' idiot.