Naw, stances won't do much to put muscle on, or increase strength. Isometrics train you to 'lock' the muscle. You use this when you change direction quickly like in basketball, or when you're stopping an incoming force like blocking in football or a grappling situation. You still want to do things like squats and deadlifts to gain size and strength, and stretching to keep you flexible.

Most people do waaay too much stance training. I've heard about 30 % of your total leg training is about right. If you do a horse stance properly a minute is a good achievement.