Two Similar Applicants applying REA

They could of course. It would depend on how your high school has done wrt Stanford admissions in the past. Your GC should know, if you have Naviance, that should give a 5-year look I think. If they’ve admitted only one say, then, unless you have a hook as others mentioned - athlete, urm, first-gen, legacy, it would be hard to go from 1 to 2. If Stanford is your first choice, apply REA and see what happens.