I see the helspawn undead and orcs get to have their own "mans best friend" , so why not other factions?

Mastiffs could be featured in banner lords as historically, they had been known to assist knights when they had fallen from their mount.

Dire wolves could feature in sacred order to extend on the winter theme. (Thanks game of thrones)

Barbarians could have something resembling a ridgeback as their dog unit.

I had not thought of other factions and their representative dog, but why should the three factions have exclusive rights to (sometimes multiple ) dogs of their own?