He would play LB like Walker plays RB for us, in an inverted form. Or Laporte's backup as you said.
He looked weird playing so wide, he is not use to it and it isn't his strength at all, but the Dutch had no choice I guess.
Think you're spot on about him playing that inverted role, got a good feeling he'll really excel there.
Very similar gait to Kompany, will be a much needed threat at set pieces.