
Feeder chooses who they throw the ball to --> first under arm throw, then can move up by making it and over heard throw to be more serve like. Whoever the ball is thrown to, that receiver must call out "mine" and dig the ball back over the net. Make harder by having the first receiver dig to the ball to the second who sets it up.
This practice has no coaching points
This practice has no progressions
New hitters rarely miss because of their arm. They miss because of their feet. Build a reliable approach, then time it with your setter.
When your hitter gets stuffed, five teammates standing and watching is how you lose the point. Good attack coverage turns a blocked ball into a second swing.
Coaches spend hours correcting arms in serve receive when the real fault is almost always the feet. Fix the movement and the platform fixes itself.