In AMA style, numerals are used for 1 through 9, but "one," when used as a pronoun, is spelled out. Easy enough. But now I'm looking at a sentence that says this:
Drug A enhances the performance of Drug B when the two are used in combination.
A colleague of mine changed "two" to "2," but I'm not sure that's right. "The two" seems to be synonymous with "(the) both," which is a pronoun.
Given all this, would "the two" be spelled out according to the same rule by which "one" is spelled out?