Were many of them in the Asian top 3 squad? (There only seem to be about 9 players in common between the Top 3 squad and the Sunwolves)
I only see Yamashida, but that's Hajime Yamashida the Sunwolves fullback, not Hiroshi Yamashida the RWC prop.
I got the sense the Cherry Blossoms' plan was mostly picking a pretty young squad and sticking with it for 4 years, but then Tui, Mafi, Hatakeyama were in the Scotland tour squad. Looks like they're willing to bring in a few reinforcements at times. In that case Argentina would definitely qualify.
Will be interesting to see either way.