As in all genre shows the members of the team exemplify or embody interesting traits of the personality. I was saying that Freamon seems to represent 'The Witness' who calmly and rationally observes what is happening.
In most genre shows the 'protagonist' (the Ego) is a conventionally good looking white man in his prime. I don't know whether The Wire was constrained to obey this model by the network, or whether it is subverting it, but McNulty is conspicuously the only conventionally good looking white man in the whole show, which makes the rule all the more stark. Also he is even heavier on the Ego, more childish, less reasonable in his relations with others, than your Mal or Fox.
Another white character I found interesting was Pryzbylewski. He was cast - surely not by chance - to look a bit like Quentin Tarantino. When introduced he is stupidly out of control, emotionally and socially,and shooting off guns at random because it excites him. I think he represents or exemplifies the 'low empathy' or 'systematising' style brain (often said to be related to level of testosterone). Prez is very good at concentrating on a puzzle for hours, until he has worked it out. In an early programme he demonstrates this by figuring out the lyrics to Brown Sugar (none of the others can penetrate Jagger's English accent) and doing word search puzzles. Later he finds fulfilment and balance as the code-breaker in the team. This is that narrow-but-intense style of thinking, which needs to be contained within a structure which can focus it on constructive problem solving, but can't handle stressful and social pressures. How interesting to have a character in a TV show demonstrating this.
And the other character I wanted to mention was Kima. She reminds me very much of Zoe in Firefly, and I wonder whether the similarity reflects something (something fairly though not unequivocally positive) about the relationships modern men aspire to have with women. In other words, a common audience need produces a similar solution.
Both Kima and Zoe act as side-kick to the ego-character. They are stronger and more competent than he is, but crucially they do not seek to compete with him. They are loved by the hero in a non-sexual way. Both are beautiful black women, more boyish than girlish. Both are in uxorious relationships which completely rule out UST. I think this must be addressing a male wish for friendly equal even sisterly relationships with women (= good) but also soothing a fear of women competing with them (=bad).