Paintball is one method of several for developing your mind to think in a combat sense. It is not a mimic for combat. Even just playing around with it you will learn some basic ideas. It has its place.
Consider it like the zero gravity dome in the movie “Enders Game”. Such a thing stimulates strategic thought, which improves general combat skills. Some would say playing chess does similar.
It would be a good complement to range time, and a real tactical training course.
With some discipline anything is better than nothing.