This loyal servant not only raised Alanna but also protects her secret at court. What's his deal?
Well, we're going to get into that. How about starting with his resume? As the narrator tells us, "Coram had been trained as a blacksmith, but he had once been one of the best of the King's foot soldiers, until he had returned home to Trebond Castle and become sergeant-at-arms there" (1.73). In other words, he's got both fighting and smith-ing chops, which makes him one all-around kind of guy.
Coram is not, however, a fan of magic. When he finds out that Maude is helping the twins with their subterfuge, he growls, "That witch would agree with you two sorcerers" (1.82). Conveniently, this fear allows Alanna to threaten to make Coram see magical apparitions to get him to go along with her plan—but she only needs magic at first. At heart, Coram is a sensible, no-nonsense kind of guy, which is really just what you'd expect from a warrior-smith.
Within a few days, Coram is convinced that Alanna can pull her own weight and will make a good page, and eventually, a good knight. If Coram had been a bit more of a liberal thinker, he might've suggested the switch himself. Before the switch, he thinks to himself: "With all his heart Coram Smythesson wished now, as he had in the past, that Alanna were the boy" (1.73). Lololol, Coram, be careful what you wish for!
And then, once they reach the palace, Coram becomes a major force propping Alanna up. When she initially feels too discouraged to stay at court, he convinces her to stay by telling her, "I never figured ye for a quitter" (2.142). And then, when Alanna freaks out about going through puberty, he gets her bandages to bind her. But most of all, he helps Alanna train after-hours, which majorly improves her fighting skills. If Coram weren't such a manly dude, we would picture him in a cheerleading outfit, cheering Alanna on as she works on becoming a squire.
Yeah, try unseeing that image.