Why don't bring one of your 4 commanders to the patrol detachment and transform it into a batallion one? you'll get +3CP
Also, take heed of the newest FAQ - saviour protocols changes the allocated wound into mortal wound (so shield drones won't matter against it). With that in mind, people will certainly not shoot the drones, as simple bolter fire will become mortal wounds if you allocate them to the drones.
Wait, you have 30 FWs, 4 BC commanders and a ta'unar and you don't have enough horde killing power? BCs and FWs ARE our anti-horde tools (Ta'unar comes base with 4 SMS and 4 BCs)!
Although, for its price, nothing in our army can beat zounds of gun drones in this task