I'm a solid ENFP and have been in the Reserves for 7 years, looking to go regular force now.
What I'm going to do is tell you what I've learned to do in my years of training, then why an ENFP would enjoy doing these things. I'll briefly discuss the strengths and weaknesses or limitations that I've encountered and how this has affected my view on life in general.
I was an Infantry Officer for 4 years and have been a Logitics Officer for 3. First, I was taught how to walk, talk and act like a soldier on basic training, then how to think in a logical and roughly linear manner for planning and executing missions based on your analysis of orders. Then training became hard.
In a 3 month course I learned how to lead a group of 8-12 people in small party tasks, performed in the field using the planning methodology I'd learned in the previous course. Here is where it all came together, going nights and days without sleep (6 days, 5 nights, no sleep, 300 calories a day), performing as a soldier both individually, in pairs, and part of the whole team, in the following tasks: navigation: navigation by night and day, living in a swamp, patrolling for information, conducting patrols in order to engage the enemy, fighting the enemy and pushing their their location, digging trenches and enforcing our position, repelling enemy attacks, urban warfare tactics, VIP extraction, first aid (simulated and real when things went not so well), marching with 75 lbs for many miles/kilometers, operating the our rifle, pistol, light machine gun, general purpose machine gun, trip flares, paraflares, participating as well as planning and conducting conventional live fire ranges with rifles, pistols, machine guns and grenades, and finally coordinate and call for artillery fire. All of the above was primarily at the participation level but in order to pass the course we were evaluated at the leadership level, because we were officers looking to lead troops. All army officers must have these skills regardless of their trade.
The 3 month infantry platoon commander course made the seem easy and was absolutely brutal. In my group of 12 guys we had 4 of us survive the first week in the field, bodies were breaking everywhere and people were smoked and shutting down so badly the advanced infantry tactics officer and subject matter expert on asymmetrical warfare came and paid us a visit on the 3rd night to tell us they would accept requests to quit instead of furthering the risk of injury. Some of us took him up on it and went home, some didn't and got broken physically in the remaining weeks. Others stayed but crumbled mentally and were removed from course. I failed off half way through on conducting hasty attacks, which I will discuss below. I have since moved on to Logistics where I was trained how to be a functional tactical operations center (TOC) officer in the role of facilitating the command net as well as the admin net, briefing commanders on the situation in a 2 min presentation, administering the logistics of 1000 personnel including emergency operations involving the procurement of chemical, biological, radiological and nuclear (CBRN) warfare conditions, citing a company of logistics vehicles to perform resupply in the field, transporting an entire 1000 vehicle convoy in a combat condition tactical withdrawal. I've learned to do a lot. Why would an ENFP do all this?
Why would an ENFP willingly do this?
We've got these visions of things can and quite importantly should be. We inspire others. We're catalysts for success and are willing to make sacrifices most would never consider. We're always on a personal quest to learn about ourselves, do good things (unless we've joined the dark side) and further other's development. We're preoccupied with morale. These are of little initial or objective value to the military, however, they are force multipliers. A platoon with high moral, who understands how they function, how to keep others functioning, growing, pushing and making sacrifices in order to achieve something that they hold dear, is a near-unstoppable force. When this is combined with the pure get-this-done functional utilitarian natural focus on the army, you produce elite troops with an unbreakable camaraderie.
There is an enormous sense of satisfaction and self worth in turning people into far more than what they were before, or were as individuals. When put to Good use, you may feel like you have found your calling. I have found my limits, mentally and physically, to be far beyond what I thought them to be at first. I am thankful for that kind of development. We ENFPs throw ourselves into things and the army requires that you do so. It's feast or famine. I thrive.
Where I wither and feel like dying inside, is in dealing with a serious lack of recognition for achievement. This has been primarily due to the environment of the reserves where they expect a high rate of attrition in their numbers over the years. You get in, do your time, get out: rinse and repeat. Therefore, not only is there a lack of superiors who are around to witness your long-time outstanding achievements, they then think it to be the norm and the recognition and praise that was given before goes silent. Having a personally rewarding job is one thing, having a thankless job is another. Being forced to do things a certain way can be frustrating but also reassuring if you learn the reasoning for it, and support that reasoning.
The system itself is a haven for those who are relatively incompetent and uncaring, who are careerists, self-centered backstabbing monstrosities of human beings and if they're above you in the chain of command, you will get fucked. Because they can. They will. It is who they are, and if they can quantify and qualify their decisions to their superiors, no one will consider listening to your concerns. This can be extraordinarily disheartening.
With our focus and drive in a given area of interest, when the interest wains the drive and focus plummet, drastically reducing our output if required to remain where we are. Arguably, this is a sound reason for not joining the military in any fashion as this will inevitably happen for an indeterminate period of time.
As for being yelled at, having to kill, focusing on the disconnected goal-oriented aspect of the military, yes, these do not naturally sit well with any ENFP, who would rather everyone simply get along nicely and are more inclined to be people oriented than results based. Having the vision supporting you in what you do, in what you want to accomplish in the military, that is an extremely supportive and force multiplying aspect of our personality. We can be the sole person who has taken the initiative to reinvigorate a large group of people, basically as their morale officer, and set the example of what you can do when you put your mind to it, that things really are okay and they will be too. It's contagious, and the support you bring others changes their world. If you get some personal thanks in private, you are alight with pride.
While I have not touched on or talked in detail about everything that has been raised so far, I do intend this to give more perspective for discussion on whether or not the military is suitable for ENFPs. I would argue it is not a good choice for most ENFPs but for some it exceptionally good.