In the combat arms, we prefer the broom handle approach.
If you ride the handle like a pony, you go armour.
If you throw the handle away, you go artillery.
If you hit something with the handle, you go engineer.
If you steal the handle, you go infantry.
In all seriousness, no one trait or combination of traits will make any individual right or wrong for the majority of jobs. The individual is suitable for a job, not his traits. This allows for a diverse team dynamic (which can sometimes create co-operation and conflict); a diverse team dynamic allows a group maximal approaches to mundane and unique situations. Furthermore, given the reciprocal nature between situation and personality, a person may have traits that do not become salient until he or she is introduced to the new environment, and these new personality traits may conflict with prescribed combinations.
This doesn't preclude certain personal traits. Soldiers need to be hard working, dedicated, courageous, team-players, and must be capable of making ethical and intelligent decisions under the most extreme of stresses. After that, it's all gravy.
