In Military Shoulder press (front) and standing barbell presses or Standing machine presses?[/quote]
I’m not exactly sure what you’re referring to. A “military press” is generally a standing barbell press to the front.
I talked about a few different shoulder pressing exercises here:
I’m not sure I’ve ever seen a specific standing shoulder press machine, but I’ve seen shoulder presses actually done using the shoulder pads of a standing calf raise machine. The neutral-grip would put even more stress on the front delts, and the leverage of the machine would probably keep tension at the bottom of the movement (though I haven’t tried it myself).
Branch Warren is an advanced competitive bodybuilder and most likely uses those variations to address specific muscles and/or uses different techniques with each.
I’d say that the overwhelming majority of lifters, like you, me, and most of the Joe Schmoes around here, wouldn’t benefit very much from doing several different types of shoulder presses in the same workout.