At the same time, Kaito understood the actions that Ayumi had taken after he disappeared, and she could no longer use his name to keep the people under control. She thought that a peaceful negotiation with the mercenaries would show them her goodwill. Consequently, they would agree to all her requests and follow her orders.
Unfortunately, the assassins Kaito hired were the best in their field. Not only were they like animals at the top of the food chain, but they were also arrogant. They would not bow to anyone who they deemed weaker than them.
To them, once Ayumi opened a path for peaceful negotiations, it was akin to showing her neck in surrender. Of course, the predators would target the weak point immediately. They would not give her a chance to gain more power.