Initially I had thought of some equivalent of Grant's Mandubian Hills scenario in which Germans were replaced by Galatians, Romans by Seleucids. I imagined the latter force being made up of mercenary hoplites and peltasts, supplemented by Persian cavalry and Syrian archers. Such a scheme would have meant diverting from my attempts to finish the Egyptian Army, however, and turning instead to painting Gaulish chariots. Since one thing tends to lead to another when it comes to painting figures I could foresee that such a step would mean not getting back to the Egyptians until 2022, probably with the Franco-Austrian War in between.
It was fortunate then, that the other day, I picked my copy of HW Parke's Greek Mercenary Soldiers (1933) off the shelf with a view to looking up something else entirely, and found myself reading the details of - or rather lack of them - Artaxerxes Ochus' ill-fated first attempt to reconquer Egypt, a campaign that occurred some time around 350BC. The fighting apprently went on for a year and culminated in a crushing Persian defeat, but - Diodorus being reticent on the topic - not much is known about what actually happened.
Parke surmises the following:-
a) That the Egyptian Army of King Nectanebo II featured a large number of Greek mercenaries, including contingents commanded by Diophantus of Athens, Lamias the Spartan and Mentor of Rhodes
b) That the Persian Army in all likelihood did not include Greeks - Artaxerxes having attempted to secure his position as Emperor by disbanding the Greek mercenary contingents of his satraps to minimise the potential for revolt.
This is not much to go on, which from my point of view is a distinct advantage. I propose a battle in which the Egyptian Army of the 30th Dynasty supplemented by Greek mercenary hoplites, takes on an army of Persians, Medes and assorted satrapies on the banks of the Nile.
Any suggestions for the troop types employed in the Egyptian Army of this period gratefully recived - though only if they are something I already have, obviously.