If you would like to add a new projectile weapon to your units, you can use the ninjastar projectile. The ninjastar is not used in the game and thus is a free projectile which can be modified to represent another projectile type. However, you must use "NINJ" in the projectile slot of the crusunitprod file.
I used it to add the recursive composite bow used by the muslums and pagans and hungarians, etc. The recursive bow falls between the shortbow and longbow. The shortbow used in the west was a simple single piece weapon without the power, accuracy or distance of the recursive, composite bow used in the east. So I needed stats representing this weapon between the longbow and shortbow and by altering the ninjastar stats, I have it now.
First, I made sure all stats between the ninjastar and shortbow were identical. Then I changed the falling stats:
range=6000, accuracy=.6 and lethality=.65, power=1. Of course, you can use whatever stats you feel are most appropriate.
Next, you can go into the crusunitprod file, choose any appropriate Muslum or Pagan bowman which should use the recursive composite shortbow and change the proj to "NINJ".
And there you go. You now have an archer unit using the more powerful recursive shortbow.
And if you want, you can add a new archer unit. I am going to create a new unit called the Saracen Muslim archer based in Sicily and southern Italy. Historically a contingent of Sicilian muslems lived in this region and served the HRE and Norman Sicilians through the High period.
Have fun
