At tvtropes.org they call Kirk-McCoy-Spock the Freudian Trio and identify Kirk as the ego, Spock as the superego, and McCoy as the id. Later they compare the superego to the angel on the shoulder and the id to the devil on the shoulder.
Although this analysis is facile when they stick to common language and don't try to relate things to their psych 101 course they often have many interesting things to say.
The Spock is an archetype that can be loosely summed up as the tendency to apply rules, reason and the greater good to all of his/her decisions. This character can exist by themselves, but more often, they will have a more emotional and humanistic counterpart to contrast their decisions. The main difference between the two archetypes is that while The McCoy will leap before looking, The Spock's solution to problems will have a balanced and well-thought out approach.
While his counterpart The McCoy is interested in doing the right thing regardless of cost, The Spock is more interested in the end result. For him, everyone (including himself) is expendable and he has no problem treating people as such.
I think that this contrast speaks well to the ethics of the egoist at the phallic trito (i.e. who traverses the father complex) vs. the altruist. Generally then, the trio would represent Spock as the phallic trito egoist or genital character who accepts himself as a peer to other adults in the community and cares about fairness among the peers and following the "rules and injunctions" of the work group that he is in. Kirk would be the phallic deutero egoist or phallic-narcissist who feels entitled to lead others despite not being the smartest, the most skilled, or following the maturation process of going from one rank to the next to get to Captain. McCoy is definitely an altruist in his role of doctor/healer and confidante to Kirk. He is definitely a subject altruist as the other two are subject egoists. I think that McCoy's irascibility generally puts him at the phallic trito as well. However, his character isn't developed enough in what I've seen to be sure about this judgment... The phallic castration complex for subject altruist can lead to the masochistic complaining that Reich indicated so well, towards the father substitute, and may account for McCoys bad mood. But, also "the twin" or idealized mother imago who represents admired qualities and boldness may typify Kirk better.
...we don't see McCoy leading and his role seems to be very much that of "a helper". The phallic trito sees the subject altruist firmly establish herself as a post-ambivalent agent and competitive being while it sees the subject egoist establish post-ambivalent love and morality. Aragorn (the ranger) in Lord of the Rings is an example of the father complex in the altruist in which he has to find the ability to be king and lead (and also seems to be having a relationship with his "sister" in the form of an elf that he was raised with as a child).
Of course, there are pre-genital aspects in all of these characters. Spock's auto-erotic trito affect block is a major part of his libidinal economy, for example.
Star Trek: Into Darkness then is a good example of the tension between the phallic castration complex and the phallic father complex in the egoist. The two remain in a dynamic relation which is also illustrated in group psychology when the guilt conscience is externalized back on to the father-substitute which, as I've written about before, concerns political views and relations to ideologues.
There is also an interesting Symptom Reading in which Kirk is a symptom and Spock is in charge and that Khan comes to represent the 'bad aspect' of Kirk in Spock.