Brandon has already shown a penchant for having characters in the cosmere hang around in various ways after they die. The Parshendi are skilled warriors, and the Shardbearer Dalinar encounters seems relieved to be face to face with him. They in fact, act honourably, much more in line with the codes of conduct suggested by the Way of Kings and the ancient Alethi codes of war.
...What if the Parshendi Shardbearer is somehow Gavilar himself, or at least shares a mind connection/memories with Dalinar's brother, psychically (or Spiritually/Cognitively, in cosmere-speak) connected to them as part of his treaty? This would explain his(Gavilar's) utter confusion of the Parshendi sending the assassin. The Parshendi may have needed to kill him in order to 'rescue' him from the intrigues of the Alethi court (which we have already seen are lethal when they go against 'the way things are done'). He has finally found his brother after all these years of living amongst a people who are truly honourable.
No one yet has a satisfactory explanation of why the Parshendi would A) know or care who Dalinar was in the first place,and why they would bother to send a full Shardbearer if all they wanted to do was find him.
