I'd really appreciate any documented occurrences of these "special abilities". 
Well, here's one example of the silly things they do:
http://www.lilwolf.biz/bm/monster_battle_apr26.htmlTroop setting for me was front, defensive, line. The SF is range 4 so the monsters were within their range and they chose to move forward. What any sensible unit would have done is a) fire at the monsters b) hold their position and wait for a better shot. Moving forward is just utterly silly since it means you'll get to close combat faster and have less time to do ranged damage. You'll note the actual archer unit did the sensible thing and just fired at the monsters when they were at the edge of their range and hoped for at least a few hits.
I'd understand the unit moving forward if they were set aggressive or even normal, but not while defensive.
