Mechanicum Combat Force Buying Guide
By GUNNZO | Published: 2026-10-31
Category: Buying Guides
Learn what's in the Warhammer The Horus Heresy Mechanicum Combat Force box, who it's for, and whether it's the right start or expansion for your Mechanicum army.
Quick answer
The Mechanicum Combat Force is a solid starting bundle for a new Mechanicum army or a targeted expansion, offering a Thallax Cohort, Castellax Battle-automata, and a Thanatar Cavas Siege-automata at a discount over separate kits.
What you get in the box
The box contains nine plastic miniatures: one Thallax Cohort, two Castellax Battle-automata, and one Thanatar Cavas Siege-automata. These represent a key selection of Mechanicum units, covering light skirmishers, mid-weight battle-automata, and a heavy siege platform.
Because the set bundles these specific models, you save money compared to buying each kit individually. This makes it a cost-effective way to field a balanced force or add a heavy hitter to an existing collection.
Who should buy it
If you are starting a Mechanicum army from scratch, this box gives you a functional core with varied roles. If you already own a Siege Assault Battle Group or other Mechanicum units, the Thanatar Cavas Siege-automata and Castellax units fill gaps in firepower and durability.
The set does not include command models or infantry thralls, so players wanting a pure infantry force or a command-heavy list may need additional purchases.
Decision rules
- Starting a Mechanicum army: Choose the Mechanicum Combat Force if you want a balanced core of three unit types at a discount over individual kits. It gives you a playable force immediately.
- Expanding an existing army: If you already own a Siege Assault Battle Group or similar box, the Thanatar Cavas and Castellax units here add heavy siege and mid-range punch without duplicating what you have. Check your current list: if you lack a siege platform, this box fills that role efficiently.
- Budget vs. specialization: The Combat Force saves money versus buying the same models separately, but you cannot customize the unit mix. If you need more of one unit type, buying individual sprues may be better.
Product facts
- Warhammer The Horus Heresy: Mechanicum: Combat Force: Includes a Thallax Cohort, a pair of Castellax Battle-automata, and a Thanatar Cavas Siege-automata — nine plastic miniatures total. You get a mix of light, medium, and heavy units in one purchase, which lets you field a varied Mechanicum force without buying three separate kits.
Warhammer The Horus Heresy: Mechanicum: Combat Force
Is it right for you?
Best for
- New Mechanicum players who want a discounted, balanced starting force
- Existing Mechanicum collectors needing a heavy siege unit without buying a full battle group
Not for
- Players who want an infantry-only or command-heavy list
- Those who already own all three unit types and need no duplicates
