Given that the KMT forces are attempting to advance rather than dug in, even aircraft cannon strafing can be rather nasty. With bombs and battleship-grade fire incoming, I wouldn't be surprised if some of the KMT units arrange "accidents" for officers who try to force the men into killzones.
While the National Army is much better disciplined TTL, and isn't doing stuff like selling their weapons to the Communists, such events, especially if repeated, may drive many former skeptics of the Union right into their arms.