I've been thinking about how to run some Arbitrators in 40K. Now, with the advent of allies, there's a lot more flexibility in how you can do this as you can steal from one army's list to help another.
You can quite easily put together a squad of Imperial Guard Veterans as Arbitrators. They can replace their lasguns with shotguns, upgrade them to carapace armour, give specialists grenade launchers and the sergeant a power maul.
Sadly, there's not much more you can do - although I might consider a Priest with an Eviscerator as a "cyber mastiff", although I'm not happy it's the best representation of what the model should be doing.
Space Marine Scouts are the other solid option - they start with carapace armour, and can take shotguns easily. Sadly, they lack the grenade launcher upgrade available.
You can also get Arbites bikers by using Scout Bikers. You get shotguns as standard and carapace armour, and some real potential for mayhem with a locator beacon.
Grey Knights & Sisters of Battle
I'm putting these in together as its effectively the same rules you're using for both - Arcoflagellants for cyber-mastiffs and Crusaders for shock squads with power mauls and suppression shields - whether from a Battle Conclave or an Inquisitorial Henchman Warband.
Both have restrictions in taking other models - the Battle Conclave is not a Troops choice so you would need to take some Battle Sisters as well, while the Henchmen either need Coteaz to make them Troops or some Grey Knights to go with them.
So, those are the units you can potentially use as members of the Adeptus Arbites - but how would you use them in a force?
All Arbitrator Force
For the greatest variety, you're probably best placed putting Space Marines and Imperial Guard allied (it doesn't overly matter which way around). You'll have a lot of scoring units from the Marine Scouts and the Veterans. If you want to up the close combat punch, using the aforementioned Priests with Eviscerators as Cyber Mastiffs.
You can certainly take a Marine Captain with a Storm Shield and Power Maul as a good Judge, and from the Imperial Guard side you can easily have a "Detective" Primaris, a Commissar Lord "Judge" or a Command HQ as a Judge with a bodyguard.
Hydras or Leman Russ are good choices for Heavy Support, with it not being too hard to justify a Vendatta as an Arbites gunship.
Marines to the Rescue
One good option for a theme list is to take a pure Codex Marines force, but with the Scouts and Scout Bikers as Arbitrators, holding out on the planet against the evil invaders - perhaps a Fortress of Redemption as the "Precinct House"?
The Marines get held in reserve, whether Terminators or Drop Pod troops - and they can then rock in to "save the planet" from the evil invaders as the Arbitrators were preparing for their last stand!
Forces of the Imperium
This is about coming up with a way of fitting as many different branches of Imperial Forces into a list as possible. Imperial Guard & Space Marines is your best bet again, but you should be able to fit in the following;
- Imperial Guard
- Space Marines
- Adeptus Arbites (any of the counts as mentioned above)
- Imperial Navy (Master of the Fleet, Valkyries & Vendettas)
- Adeptus Astra Telepathica (Astropath, Psykers)
- Departmento Munitorum (Commissars)
- Adeptus Ministorum (Priests)
- Adeptus Mechanicus (Techpriest)
I have some ideas on how to kitbash a few Arbites, but that is definitely something for the future. I hope these rambling thoughts have been helpful. Does anyone have any other suggestions for units?