Mind. Blown.
edit:
To add on, I think Dalinar is being more literal here. If the Stormfather is holding (or, more likely, IS) a piece of Honor's shard, which I feel is strongly implied, he just enhanced his connection to it through the Nahel Bond. Thus, he has partially taken up that piece of the shard of Honor himself. Maybe this one piece of Honor has the intent of Unity, rather than the larger implication of Honor+Cultivation = Unity. So depending on how many pieces Honor split into, there may be separate intents to each, which all combine to make up Honor.