Zaos would rather be naïve than do things that won't let him sleep at night. He didn't become a soldier to do atrocities, and while he wasn't that idealistic, he knew that his job was to protect the weak, not attack them. He had attacked people many times, but in all those times, his goal was to protect someone...
"… Attacking kids with crossbows might be dangerous. The chances of them dying will be higher, so we will avoid them for the time being," Vitalar said. "However, don't think that we will be able to act like this forever."