Well some believe Fe to be more caring and would think that this would make a bad soldier. Yet Fe is actually more about expressing your emotions outward which can be a whole range, not just love. Anger and hate also get expressed. This wouldn't make a good soldier I guess but it doesn't exclude them from the profession. Also a well developed Ti and strong J would make an excellent tactician.
http://www.cognitiveprocesses.com/extravertedfeeling.html
I believe your description of Fe to be incorrect.
"The process of extroverted Feeling often involves a desire to connect with (or disconnect from) others and is often evidenced by expressions of warmth (or displeasure) and self-disclosure. The "social graces," such as being polite, being nice, being friendly, being considerate, and being appropriate, often revolve around the process of extroverted Feeling. Keeping in touch, laughing at jokes when others laugh, and trying to get people to act kindly to each other also involve extroverted Feeling. Using this process, we respond accordingly to expressed or even unexpressed wants and needs of others. We may ask people what they want or need or self disclose to prompt them to talk more about themselves. This often sparks conversation and lets us know more about them so we can better adjust our behavior to them. Often with this process, we feel pulled to be responsible and take care of others' feelings, sometimes to the point of not separating our feelings from theirs. We may recognize and adhere to shared values, feelings, and social norms to get along".
quoted from a passage by Linda V. Berens direct and founder of interstrength associates and has 25 years experience qualifying trainers of the MBTI as well as...well a long list of other stuff, also holds a Ph.D. in psychology. Also taken from Dario Nard, Ph.D. holder founder of UCLA's Human complex systems program and has been working with type and temperament since 1992, has also been heavily involved with the Temperament Research Institute since then.
From your description I think...maybe you got Fi and Fe mixed up?
Fi:
"As a cognitive process, it often serves as a filter for information that matches what is valued, wanted, or worth believing in. There can be a continual weighing of the situational worth or importance of everything and a patient balancing of the core issues of peace and conflict in life's situations. We engage in the process of introverted Feeling when a value is compromised and think, "Sometimes, some things just have to be said." On the other hand,most of the time this process works "in private" and is expressed through actions. It helps us know when people are being fake or insincere or if they are basically good. It is like having an internal sense of the "essence" of a person or a project and reading fine distinctions among feeling tones."
quote from the same people stated above.
----------------------------------------------------------
Any type could be a good soldier just like any type could be a bad one but if we're going with stereotypical types....
It's difficult to really say what types would make good soldiers but I would say extroverted types mainly, types with Se as primary given the nature of Se, so ESTJ's would seem pretty good cause of the Te,Si combo also ESTP's Se and Ti really would make a nasty combination in a soldier (..by that I mean nasty as in theoretically a good soldier way

), for some reason I think ISTJ's would make good snipers with the Si, Te combo of course you have INTJ's I mean they're type are sometimes known as the "strategist" lol Ni,Te combo, also less not forget INTP's for strategists, I'd imagine they would work quite well with INTJ's in that manner (not sure about socially but work wise they would help each other or it would seem that way) with the Ti, Ne combination.
I wouldn't have thought that INFJ's would make good soldiers Ni seems to be a slow process and Fe sounded seem that good on a battlefield, however INFJ's as negotiators now that seems better suited maybe something more covert? but I dunno, being able to manipulate people and turn people would seem to be within the abilities of an INFJ, most INFJ's seem to have a hard set of morals to no go that way but it wouldn't be out of reach as far as asking if they could be able to do something like that is concerned.
Type isn't everything though, there are a hell of a lot of factors to take into account, the environment the person was raised in and so forth so, bit of a difficult question to answer.