I think that's a solid choice. Interesting that Matt Ryan was the clear #6 (or at least the second choice for #5) based on stats. He's probably a little underrated in general. Warner is basically the Madison Bumgarner of the NFL - good in the regular season, something else entirely in the postseason.
Rivers and Roethlisberger are basically the same QB - their stats are almost identical, though their teams' postseason records definitely are not.