Volleyball drill: side-out/rally ball with coordination block/defense

On the 'team-side' there are 5 players: Sv., center, libero, passer/runner and diagonal.  
On the other side there are two trios. One trio is going to block and one trio is going to serve and defend. 

The service pass is provided by the libero and passer/runner. Sv. comes from position 1 and has a choice of three attackers; pos. 2, 3 and 4. 
After the service follows a rally ball, in which the Sv. remains standing. 
Then again, but now the Sv. starts as a front player, making the choice pos. 1, 3 and 4. 
If the diagonal is a front player, all blockers stand 1 to 1. If the diagonal is behind, then supportive blocking is done on pos. 3. 
This also requires the defense to be adjusted. After 4 balls, the trios change front and back. 
After some time other players on the other side.