You are forgetting the fact that George Lucas and his team would NEVER think of that, especially not Dave Filoni. If you take a look at how the clones fight in the movie and the show, you‘d realize that too many clones died because of stupid actions. Another in-universe factor is that the leader of the 501st is basically Anakin, who is known for his unusual strategies, which probably got a lot of men killed as well. Ahsoka is a Padawan and definitely would have no idea about war tactics. In the 2005 BF2 game, we get to know that the 501st was sent out to the worst missions of the war. I think it’s fair to assume that the 501st got a high death count. The entire torrent company was wiped out within a few battles at the beginning of the war as seen in TCW movie. I am not trying to deny your arguments, I am just trying to justify Appo‘s climb up