To accumulate military achievements, gaining rewards from a confrontation on the battlefield will suffice.
However, speaking of it is easy; doing it is not, as there are many people on the battlefield, especially for those first-timers without experience. Getting injured is inevitable. If one's fate is unfortunate, it's possible to meet misfortune on the first battle.
For Jiang family to believe that Song Lingzhao accumulated these military achievements without a single injury is self-deception; even a reincarnated war god wouldn't be so capable, especially for a fourteen- or fifteen-year-old child.
But since the letter didn't mention this, it's hard to guess; one can only hope for the best. For Song Lingzhao to send a letter of congratulations indicates that everything is moving in a positive direction.
But Jiang family has a mother, and worry is inevitable.
