You never cease to impress, just one point regarding the terrain in the Indus region however: Is the transition between lush forests and arid mountains supposed to be that abrupt?
Also, didn't Darius' canal go along the Pelousiac Nile, which went further to the east, closer to the modern Suez? I am not sure on that one, but I remember that the hardest obstacle for invading Egypt was the Pelousiac Nile which was the easternmost of the Nile's 'limbs', and you had to cross it to enter Egypt. For example Perdiccas and Antigonus had severe trouble crossing it. As it seems from the in-game map, both yours and the vanilla one, there really is no river to cross to enter Egypt.
Also, didn't Darius' canal go along the Pelousiac Nile, which went further to the east, closer to the modern Suez? I am not sure on that one, but I remember that the hardest obstacle for invading Egypt was the Pelousiac Nile which was the easternmost of the Nile's 'limbs', and you had to cross it to enter Egypt. For example Perdiccas and Antigonus had severe trouble crossing it. As it seems from the in-game map, both yours and the vanilla one, there really is no river to cross to enter Egypt.