Did Odium Splinter all the Shards for the same reason?
Brandon Sanderson (paraphrased)
No. Some Shards he Splintered because he feared the Shard itself, and some Shards he targeted because he feared the Vessel. He was working his way down his list in order of the Shards and Vessels he felt would be most dangerous to his plans until he got stuck on Roshar.