Thank you to Massad Ayoob for codifying the Priorities of Survival (mindset, tactics, skill, & equipment). This is one of the foundational paradigms I use to analyze and evaluate events, scenarios, training, tools and many other things.
They are listed in order of importance and mindset is king. However, they can't be separated from one another. While mindset is most important, confidence is the key to having superior mental conditioning. Where do you get confidence from? You get it from having an understanding about how to manipulate space and people (tactics). You get it from the blood and sweat expelled during years of exhausting skill development. You get it from having robust and reliable equipment that enhances your ability to execute your tactics and skills.