Heraldry question for an SM2 Blood Raven from someone who hasn't played tabletop or painted miniatures.

I've got a decorated Blood Raven heavy with wraithbone helmet, runelord brass pauldrons, aquilla, relic weapon skins, and abundance of seals I'm making, and I was wondering whether I should use the fire support chevron or veteran cross on the right pauldron.

In my head I think it would be kinda cool for him to have been a firstborn devestator who survived the rubicon surgery and became a primaris eradicator to justify the use of Mark X gravis armor with a Mark VII helm.

I'm trying to figure out whether the veterancy cross or fire support chevron takes precedence in this case.