As a soldier, Long Qian Xing himself had his own set of goals and thoughts.
It was impossible for one to become a soldier just because they wanted it. Being a soldier was not easy and the harsh training he imposed had already scared a lot of people to run away and go back to their own home.
After all, they were not used to live in such situation. Yet, they were forced to do it because they have their own reasons.
One of the reasons why Long Qian Xing wanted to become a soldier was to protect the people's happiness.
If they were attacked by others, how could they live peacefully and happily? There was no way something like that could possibly happen. And it was the soldiers' duty to protect the border and the people who lived inside.
He wanted to protect them too.