Have two players on each side of the court. The player at the front sets the ball in the air and then moves out of the way for the other player to set the ball to the other pair on the other side of the court.
Position changes are very common in volleyball. Setters must know that they would never receive two of the same quality passes one after the other. They must adjust and be ready to step forward, backwards or to the side, and this must not interfere with the efficiency of their setting.
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.