Because of their superior speed on the tactical map I always found drones without any weapons or warheads were best used to blockade the worm holes/warp points. Enemy ships would just chase them around until one or the other ran out of resources.
Seems like exploitation of the AI's limited capabilities. Not much of a strategy and a waste of resources jars. If you had played with 'finite resources' [on] you wouldn't be wasting resources on such items.