I've read somewhere (I think at the Common Mount equipment description) that you can take a trait to give your common mount a single trait, and that this could be either a faction or class trait.
If taken as faction trait, would this take up one of the allowed/required choices for that domain? For example, when picking up Powerful Charge: Charger 1 from the Ovis kingdom as a faction trait to apply to the common mount, would this count as one of the 1-3 required traits for the Kingdom/Regional traits?