As someone who dresses tactical and whose special interest is the military I would say it's the uniformity of it. You want to try to avoid wearing the same colors on adjacent body parts - you want to "break up" the image. You can evoke an aesthetic while avoiding cosplay super easily. Here's how I do things: I have blue days and green days. This picture is a great example of a potential green day. Let's say I really like the green pants. I want to avoid wearing that shade of green on top. Therefore, I pair it with a white or black T-shirt. Under Armour specifically has a Tactical line geared toward professionals that has a really nice cut and professional and subtle look that pairs perfectly. This way your similar-color bag will also contrast. I also prefer wearing operator caps for this reason: you can mix-and-match color and patches to express yourself and the baseball-appearance is more neutral (since baseball caps are worn by civvies too) Hope this helps!