I hope the ones with axes are Gazi Infantry; I miss those guys!

I think the screenshot might be a bit heavy on the palm trees (yeah, I know a fair number grow along the Nile, but still), and I too am puzzled by what the projectiles are supposed to be. That said, however, overall I still think it looks pretty good. As for the artillery, my guess is CA set up a custom battle and just wanted to show them off. Of course, as Zenicetus pointed out, the English could simply have brought siege weapons with to take whatever city they're intending to conquer; and that the Egyptians dispatched an army to intercept them before they reached their destination.