The same basic Cadian infantry figures can be used to create either a Brood Brothers squad in the core Genestealer Cult list, or if you want to run a full Astra Militarum detachment, they can be run as a normal infantry squad. Depending on how you build your squad, there's a bit of a catch, though. There's a slight mismatch in the allowable weapons loadout for a Brood Brothers Squad as compared to the standard infantry squad.
- Both squads have a sergeant, or equivalent, that can be armed with a pistol and melee weapon if desired
- Both squads can take a vox caster
- Both squads can have two models form a heavy weapon squad
- The Cult Brood Brothers squad can have two models take a flamer and/or grenade launcher, but in the infantry squad, only one model can have an item from the Special Weapons list (which includes not only the Flamer and Grenade Launcher, but the Sniper Rifle, Meltagun, and Plasma gun).
I'd originally built up my first two infantry squads as pure Brood Brothers squads with both a Flamer and Grenade Launcher. However, if I want to run them as Astra Militarum Infantry squads, I need to drop one of the Special Weapons and demote that model to a lasgun. Hence Mutt and Jeff (only their mother can tell them apart, apparently).
These guys are painted up using my standard paint scheme for my Imperial Guard, and will typically only get used when I'm running a full Astra Militarum detachment (or if I decide to go completely crazy and run a pure Imperial Force (albeit of the four-armed variety).