Actually when you come to think about he's right.
The purpose of scorched earth is a slash and burn tactic. It's to hinder the enemy when they get there. Take Napoleans invasion of Russia for an example. The French army was moving into Moscow. So most of the Russias just packed away and took everything they could. This severely reduced Frances numbers. And when going back they we're ambushed. At least I think that's true.
In this case, English troops scorch earth to hinder France. England peaces out with Scorched earth, gives France the scorched earth lands. Theoretically this should work. When they get those lands they'll know that there is nothing left.
So yeah I would say OP is right.