I made this mod a while back after finding that umbra could be defeated easily by a marksman easily. This mod adds a powerful bow to umbra so he can deal with those pesky marksman\mages. Also he swithces between the Umbra and the bow automatically based on your distance from him.

http://download.fliggerty.com/download-64-700
http://morrowind.nexusmods.com/mods/42253