My first example is instructors who are actual combat veterans who are wanting to use the skills they learned to teach people how to survive. They start out teaching people how to be soldiers, which is pointless and niche as all hell. I then see that they mellow out slightly by evaluating ways they fought and showing why simple things are rulers of a fight instead of the high speed cute stuff. But at some point they shift into this modern operator wannabe that wears this new gear that they never had experience with. They stick to one gun that some operator says is the best and they adopt the C clamp just because it is the newest thing and they want to feel like the operators on the 5.11 commercials.
The biggest challenge I have faced since I have been out is keeping my feet planted in reality. I believe that people like Travis Haley, who have been out for too long, start to get what I call "static range vision" where they forget what combat and firefights are like. They get so fixated on their shot timer and rifle MOA that they forget the fact that the one thing that will determine 99% of the firefight outcome is being adaptable and having the will to fight. Luckily I have not forgotten this.
I have analysed my experiences from my time fighting, and this led me to prefer bullpup rifles and completely omit drills as valid training aids. I found that the hammer pairs/failure drills everyone obsesses over are useless when your life hangs in the balance. I found that hits are all that count and you better make sure they hit. Shooting 30 rounds in 4 seconds doesn't do you any good when you hit only twice on a running person. These competition shooters who focus on getting a sub second failure drill are demonstrating a high degree of inexperience and ignorance.
I could probably write a 200 page book on my experiences and what I found to be effective and why, but I will just leave you with this minor rant. If you wanna hear or read more, you may request more on my YouTube channel or here in the comments. I would be glad to answer your requests.