Julius Caesar was in Egypt a few times, and it's not far-fetched to think the next Caesar might have repeated it there when he was conquering the place, or that it was a widespread meme greeks and romans used, so it's technically not anachronistic. It's rather just irrelevant to native Egypt. Julius Caesar said it in Italy, and the phrase was invented by a greek guy in Athens.It's a joke dude, I know rome conquered egypt
(technically it's still a bit anachronistic as alea iacta est is attributed to caesar and rome didn't conquer egypt until a decade after his death, but that's just splitting hairs)
It's fitting for the game, but it still takes you away from Egypt.