I noticed some similarities between Martin and these people.
- Between St. Martin de Porres & Martin The Warrior:
St. Martin de Porres is said to have been friends with St. John de Massias [sound familiar?] and St. Rose of Lima.
- Between St. Sebastian & Martin The Warrior:
Martin The Warrior was tied between two posts and left to be killed by the birds in Martin the Warrior (book). St. Sebastian was bound to a tree [much like a post] and, after being shot with arrows, was left for dead. But both of them survived afterward and escaped by the means of someone else; Martin The Warrior by Laterose, Brome, Felldoh, and Grumm Trencher, St. Sebastian by a compassionate older woman.
- Between St. Michael & Martin The Warrior:
Both have appeared in visions to warn someone. Martin is known as the protector of Redwall Abbey just as St. Michael is known as the protector of Heaven. Both of them fought [technically] 'The King of Demons' and won.* Both are known as images of goodness. Both of them are depicted in art, standing over their dispatched enemy.
He also has some things in relation to other Biblical characters. For instance, Moses, who killed a man who had been whipping a helpless laborer in Egypt. Martin did [ok, 'tried'] the same thing, wrapping a whip around the vermin's throat.
In all, just to sum it up, I think Brian Jacques made Martin to be a mix of a couple well-known and famous beings from Christianity. I also believe this enforces my argument on Tree Climber's blog: Religion of Redwall part 2
.*-[Although it was actually Matthias that killed Asmodeus, it was Martin who snapped him out of his trance, enabling him to kill Asmodeus.]