None of the Dorne or the Sand Snakes story have any bearing on the who will sit on the Iron Throne or the security of the overall realm. I suppose if Jaime and Cerseis daughter were killed it might start a new war between the Lannisters and the Martells. Zero intrgue, the sand snakes do not seem very dangerous or skilled fighters, and Oberyns lover is coming off as bat shit crazy. Oberyns own brothers and king of Dorne, while not happy about his brothers death at least understands that was death by combat that his own brother volunteered for.

Just end the whole Dorne storyline in the next episode and spend more time on the other more important players.