Originally Posted by
The Dude
People get caught up in the fact that he sometimes wears plain armour; he still has a real nice set of ceremonial plate (which is how FW will present him). He is also still bigger than a normal Marine. With Alpharius, it isn't about him being different from the other Primarchs, or more like a regular Marine, it is about him forcing those around him to perceive him as such.
At least his rules are out now Kings; the Khan won't be out until 2020...