Am I missing something? Are you trying to bind a Force 9 spirit? Only then does the spirit roll 18 dice. To summon a spirit the spirit only gets Force dice but the DV is hits*2.
The original situation was somebody dealing with a surprise drone. Not necessary to bind a spirit if you're just summoning it quickly. Hell, if you're being attacked by a drone, then I doubt you have time to gather resources and bind the spirit. If you want to pre-bind it, then you should have plenty of time beforehand to recover from the drain.