As soon as you place a yellow square start the induction to get a probe droid and spawn one. Don't wait for someone to call for a spawn, the group below needs to always be able to handle rapid probe spawns. It might also help you if you send a DPS class up top with whoever is doing the grid to kill the first add faster, allowing them to spawn the first probe faster. Lastly make sure you aren't wasting DPS on Assassination Droids, just have someone run into them away from the group.
Can any (Rakata geared) class survive the explosion with a sorc shield up? (from running into an assassination droid)