One server stands behind the opponent's baseline and two setters stand in Zone 2 and 3. The receiver is supposed to underhand pass the served ball to the setters alternately.
Every four passes rotate players so they become servers, setters and receivers. In this drill, receivers must keep low position and control ball direction.
You may set 2 servers so they would serve one after the other like a 'machine gun', giving receiver little time to prepare and react.
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.