The Martial Union wasn't interested in a long-drawn conflict that would stretch out for many months to half a year. The goal of this entire conflict in the first place was to demonstrate the power and utility of their long-range techniques and draw out the greed of the G'ak'arkan Tribe for those techniques so that the next time that Rui makes an attempt to negotiate with them, it would go much better than it did before.
That was why Rui had no problems rushing the conflict between the Martial Union and the G'ak'arkan Tribe to the next level. After all, once the conflict between the two groups reached its peak, then their little exhibition conflict would be done, having exhibited everything that they need. At that point, the conflict was no more than a liability that did nothing but sapped away the capital of the settlement.
