I am not so sure, if the defender tries to avoid trading Pawns as much as possible, but instead pushes these forward when they get under attack. It only requires two interlocked Pawn chains of opposit color to make an impenetrable barrier.
I don't claim to have anywhere near your experience and expertise, but I find it hard to imagine that a player could build an "impenetrable barrier" of Pawns, especially when that wall of Pawns is being met by an attacking wall of Pawns. I'd think it quite hard to stop an opponent from either capturing or passing a Pawn. I'd have to see your evaluation demonstrated.
I don't claim to have anywhere near your experience and expertise, but I find it hard to imagine that a player could build an "impenetrable barrier" of Pawns, especially when that wall of Pawns is being met by an attacking wall of Pawns. I'd think it quite hard to stop an opponent from either capturing or passing a Pawn. I'd have to see your evaluation demonstrated.