Greek Fire would've been a cool addition to FOG2 Byzantines ... although mostly used in naval engagements if I remember correctly?
Yes, Greek Fire was primarily a naval weapon because a large enough siphon apparatus to fling it far enough to be effective was pretty big and clunky, not to mention dangerous to handle.
There were infantry Greek Fire siphon throwers but it was rare and I can't recall the circumstances; again because the apparatus was heavy, clunky, and touchy. Too be fair, any game which simulates them should allow for siphoneer self-immolation probabilities when disruprupted by enemy missiles or melee. Greek fire was truly a two edged sword.
Isn't there an Islamic naphtha thrower unit if FOG2 though?