[giantrobot]

Cables drones would (and likely do) make better relays than as attack drones. A relay drone flies out to the horizon and relays the LoS signals to an attack drone flying over the horizon from the perspective of the base station.

The relay then gets to spend far more of its power budget on the relay-drone segment and has a very low power relay-base segment. Relay drones also perform surveillance while they're on station. Better bandwidth to the base station from a "wired" connection means a higher fidelity feed or potentially additional cameras to cover a wider area.