It was not that the Dagger clan was not strong enough. In fact, not just now, but at the time of the invasion into the Chikitsa clan territory, they were eight times the size of the Chikitsa clan, but unfortunately, they still lost.
This, however, was due to the generational use of a particular biological weapon that was called the Tamashi.
The loss on the side of the Dagger clan was so massive that the submissive clans to them saw their loss as an opportunity to break free and rebel.
Which in turn caused far more losses for the Dagger clan.
There were suddenly in a position where allied forces had turned against them and they had lost a huge chunk of their power to the threat that was a Tamashi.
This served as one of the biggest lessons to the tribe.
In fact, it was so deep that it was taught to children as bedtime stories in other for them not to repeat the same mistake again.
After all, it was a time in history when the clan was almost completely wiped out.