The battle was rough, losing 60 men and women was even rougher especially since they were Zamerians, people who come from another Continent. Although they are in no position to complain and act given that they come from poor backgrounds, King Michael does not want what now are the majority of his people demotivated.
Zamerians picked up the Budget, and raised it up for the better which is the prime reason why King Michael does not want to look bad in front of them, that's why all that gold was given out and that's why he will continue to offer them more stable lives.
Furthermore, we can't blame King Michael for these deaths. The blame can be solely placed over Grand King Talato of the neighbouring Country, Meridionali Ignis.
It is Talato who wants power, it is Talato who wants more gold and it is Talato who sent out 600 Soldiers here to reclaim Gaster Kingdom if King Michael doesn't agree to his [Talato's] demands.