Both stories involve the maturation of the main characters. The boys in "Lake" experience trauma and see the face of death and grow up as result - they no longer want to be "bad characters". Lt. Cross goes through a similar growing up process, understanding through the death of his fellow soldier, that there are times when he must abandon his dreams and focus on his duty.
The unclear nature of morality is also similar. In "Lake", it is clear at the start that the boys don't really want to cause trouble - they are just out for a good time. However, readers could argue that their flippant attitude is immoral in itself, especially as it leads them to perform immoral acts. The do become "bad characters", but by dawn they are repentent - leaving reader to question how they should be judged. In "Carried", the characters are portrayed as average and, overall, good men. However, as part of war, they commit heinous acts of violence. So are they good? Are they moral?
The point of view of the two stories is quite different, however. In "Lake", the mature narrator is telling the story of his experience when he was younger. In "Carried", the narrator is outside the story and is omniscient, giving the views of all the characters. The first provides a more personal experience for the reader; the second, a more observatory experience, as if examining the situation like a scientist.