Just to confirm something with other Deathwatch fans.
Is the number of weapon systems that a pilot or gunner fire always one? Bar "power of the machine spirit"?
I had always taken it as so. It does mean vehicles like the single-crewed Stormraven cannot use all of their weapons at once, unless there are secondary controls for people besides the pilot.
I had stumbled across this thread which had some interesting ideas about land raiders and inspired me to check.