Character Analysis
If Ella was Malcolm's mother figure, and Elijah Muhammad was his father figure, then these guys were like his academic advisors. They're the ones who push him to get out of the hustling game and get himself educated.
West Indian Archie
We think that West Indian Archie was probably such a bad-mother-shut-your-mouth that he would've scared Shaft. We mean, they called him one of the Four Horsemen a.k.a. the guys that bring about the end of the world. He's not someone you mess with.
So we're pretty sure when this scene happens, Malcolm isn't thinking that he's going to be a mentor:
"Red—I want my money!"
A .32-20 is a funny kind of gun. It's bigger than a .32. But it's not as big as a .38. I had faced down some dangerous Negroes. But no one who wasn't ready to die messed with West Indian Archie. (8.4)
We know how that sounds, but he's actually very sweet, we promise.
Bimbi
Malcolm meets Bimbi in prison. He was a burglar who had been imprisoned for what seemed like a really long time. People were so scared of him that he didn't even have to use physical force to get his point across. Again, not exactly the type of guy you'd look to for wisdom.
Mentors
As unlikely to be mentors as they might seem, Bimbi and West Indian Archie push Malcolm onto the right path using whatever means necessary. They're almost like a tag team, because West Indian Archie gets Malcolm into prison and Bimbi takes care of the rest once he's behind bars.
What you have to know about these guys is that they are not just thugs, they're really smart. Take West Indian Archie:
West Indian Archie had the kind of photographic memory that put him among the elite of numbers runners. [...] I've often reflected upon such black veteran numbers men as West Indian Archie. If they had lived in another kind of society, their exceptional mathematical talents might have been better used. But they were black. (8.4)
If he wasn't black he might have been a famous mathematician, a scientist, or who knows what. But he was black, so he was a gambler.
While West Indian Archie is a numbers man, Bimbi seems like he's more on the Humanities side of things. Malcolm says:
He would prove to us, dipping into the science of behavior, that the only difference between us and outside people was that we had been caught. He liked to talk about historical events and figures. When he talked about the history of Concord, where I was to be transferred later, you would have thought he was hired by the Chamber of Commerce, and I wasn't the first inmate who had never heard of Thoreau until Bimbi expounded upon him. (10.26)
History, Sociology, Philosophy, Bimbi probably could have been a professor on any of these subjects if it wasn't for the color of his skin.
But when both of these guys meet Malcolm, we guess they see the potential for him to become more than they were able to. Maybe they thought that, unlike them, Malcolm would be able to use his intelligence to have a positive impact on the world.
So even though everyone else thought that Malcolm was just a cold-blooded killer, West Indian Archie surprises him by saying:
"You’re thinking you're going to kill me first, Red. But I'm going to give you something to think about. I'm sixty. I'm an old man. I've been to Sing Sing. My life is over. You're a young man. Kill me, you're lost anyway. All you can do is go to prison." (8.36)
Just that little speech stops Malcolm from killing West Indian Archie and potentially spending his entire life behind bars, just like Bimbi. Later, West Indian Archie tells Malcolm that he never wanted to fight with him, and that he always liked him. So it seems like he was trying to make Malcolm realize that his current way of life would only lead to jail.
Bimbi sees the same potential in Malcolm. He's using his intellect for bad things again, cursing out God and everyone around him, when Bimbi tells him to put it to better use. He says:
Out of the blue one day, Bimbi told me flatly, as was his way, that I had some brains, if I'd use them. I had wanted his friendship, not that kind of advice. I might have cursed another convict, but nobody cursed Bimbi. He told me I should take advantage of the prison correspondence courses and the library. (10.28)
Just like West Indian Archie forced to come out of Harlem, Bimbi forced him into the library. And the rest, as they say, is history.