I can find very little evidence to substantiate this claim, to be honest. Stralman has been good for us, after bombing out at Toronto, Columbus, and then failing to get a roster spot on the Devils blueline. In his last 100+ games here he has 14 points. If you look at time on ice, PK responsibility, ect over the past half decade, Klein has him.
It's pretty clear that Stralman has evolved into a defensive defenseman, but he isn't as good at it as Klein. You play Klein with Marc Staal right now and he'll look pretty good as well.