Yes, I understand all that and I used it before in my games.
But I thought in this specific game it doesn't work. After the restriction of the movement of the white pieces, white has serious threaths to capture crucial black pieces. Of course I can be mistaken. I am probably too fast with my conclusion it is a draw, but then again even ughaibu was wondering if I really could win the endgame.
I will have a look at the game again. For now let's say it wasn't a good example, but the idea becomes clear when we imagine black has less soldiers: he has the king closed in, but is unable to restrict white's two pieces enough to kill.