at 6:31: we're letting no. 3 after doing the away screen cut through the zone for a possible kinda give 'n' go with the low post player. players on the weak side are filling the spots
You are right. As long as Player 1 gets an open shot in corner 3, there is no reason to leaves this spot. My intentention was to emphasize that the perimeter players should move in order to maximize the space between them and their defenders and create an easier pass for the ball handler.
Cutting through after the away screen is usually how you do it after a pass to the post player. The downside is that you bring another defender close to the low post player. Timing and communication are the keys.