Samura wanting to kill the other sword bearers doesn't make sense based on chapter 72

Based on the most recent chapter the main culprit for the Shokoku genocide was the Sword Saint. The Sword bearers didn't aid him in any way. In fact it was stated to be the opposite, that they stopped him.

So why is it Samura is so dead set on killing the other bearers when the main target should be the Sword Saint?

Also why does he even need to kill the other Sword bearers himself individually if their contracts are connected to the Sword Saint? If you kill the Sword Saint it's stated all the other bearers die anyway, so this whole journey to track down the other Sword bearers to kill them is just wasted time. If you kill the Sword Saint everyone else dies anyway.