Mistaking cautiousness for timidity.
That is the mistake that Valgrun had made
As long as the western border tribe of the southern Great Steppe did not threaten their status as the strongest in the western border area of the Southern Great Steppe, there is not many things they would meddle in
And from dealing with Bolghar tribe, Valgrun knows that the Bolghar tribe only need minimal effort that they need to do for the status quo to stay the same
They either defend, or cooperate with the other tribes to cut down the disobedient tribe to size
There is many methods they could employ while remaining out of the conflict.
His method was cautious because there was never a need to take the risk. But when it is time to take a risk, Bolgharu like his character is very decisive.
Valgrun could guess that the reason why Bolgharu take such chance is because he believe the risk is proportionate to the rewards that he would get if the risk succeeded.
