User blog comment:Master Sima Yi/Assassinews 05-08-'14 – Assassin's Creed: Rogue announced/@comment-4786308-20141013160942/@comment-3046679-20141013212836

I think the deal with Achilles' voice is the same as Ezio voicing Batman in Origins - "Yeah, we could have had Roger Aaron Brown do a slightly younger impersonation of himself, but we decided not to, for whatever reason."