I think it would be far more difficult to take down a plane than an airship given the enormous difference in velocities. Even at takeoff, a drone-sized IED would probably only be fatal to a small part of the plane's occupants, while it could probably 100% destroy a hydrogen airship in flight.
That said, I don't see any reason we'd need to put humans on these, so that probably lowers the risk massively.
That said, I don't see any reason we'd need to put humans on these, so that probably lowers the risk massively.