Re: paleologos workshop link
It depend if you want to be accurate or not. If yes, I really don't think they had such kind of signs in battle to recognize themselves. Before uniforms appeared, it was more a simple sign like a small cross on the heart or behing the shoulder or a coloured armband.
On the other hand, gameplay wise, it may help. But in that case, I think that it should be smaller.
Under the patronage of Flinn, proud patron of Jadli, from the Heresy Vault of the Imperial House of Hader