Met these guys today. Every single shot was a head shot.
I have played with Pengu.Penta like twice now and I played with a Kubeee.Flam3rs also. I think they are both in the pro league. They peek every corner slowly by strafing left and right while aiming at head hight moving their aim from left to right in the room or vice versa. So they don't fully expose themselves to the whole room right away. On the contrast, when they know where someone is they seem to sprint a lot and rush, pre-firing or aiming where you are or were. Avoiding hesitation or not full commitment to a peek seems to be key.
I did a theatrical performance about puns. Really it was just a play on words.