"stat_ground" combat bonus?

[Bucefalo]

As far as i know (i read it a lot of time ago in total war center), the combat bonus of terrain apply only to melee, and only increases the defense, not the attack.

You may want to do a search in the twc forums, i think there was a sticky somewhere explaining this. Here, i found it:

http://www.twcenter.net/forums/showthread.php?t=225753