Tau military doctrine does allow drones to be used as suicide weapons.  Post Damocles Crusade, they developed their own equivalent of torpedoes which consists of a massive swarm of drone piloted missiles.  The weapons have incredible speed and range, and trump pretty much any other guided missile, but their launchers require bulky gravitic accelerators, and they're hideously expensive to replace, since you're popping out something like 40 missiles a salvo.<br/><br/>As a quick note, I wouldn't be discussing this sort of thing if there weren't a chance it would show up in game.   ;)<br/><br/>Similarly, Tau weapons will be using the Deathwatch errata stats, meaning that they're kinda scary.