Here is the grand list of all shortbows in core IWD which are better than vanilla +1:
. . . . . . . . . . . . . . .
Amazing, huh? OK, now check out the shortbows available in the expansion:
* Storm Bow. It's a +3 short bow that requires 15 STR. * Shortbow of Ebullience. A +3 shortbow with (average) 1 extra fire damage per shot, and best of all gives an extra attack per round. Oh and you get -2 CON and -50% fire resistance. Hilarious. * That's all.
Devs, please give us some decent shortbows in the main game. They don't have to be broken like messenger of sseth. Just make them worth picking up.