From the introduction:
This is a combined Jump for AC4 and ACfA. Your journey begins six months before the events of Armored Core 4, the Lynx War. For the purposes of this Jump, the games’ timeline will be compressed, and the Economic War and all that happens in Armored Core for Answer will happen within 4 years of the Lynx War concluding or begin by your sixth year, whichever comes first. Of note, Anatolia’s Mercenary does not exist in this world by default; they were ‘you’ when you played the games, and by such, you are certainly encouraged to take up that role if you so choose. Keep in mind that if Anatolia’s Mercenary does not exist, the events of the Lynx war may go very differently… or not.