Quote Originally Posted by hoom
I think its an intentional distinction between retreat on the strategic level (because they knew you outmatched them) and the tactical level (when only after seeing your army/maneuvres is it clear that discretion is the better part of valour).
I'm pretty sure it's related to the fact that it calculates units with missiles as being more powerful at the start of the battle (with their full ammunition) than for the sake of autoresolve, with Armenia in .74 I ended up getting attacked with even odds for an autoresolve but when I started the battle, my horse archer army had a 3:1 advantage so the Seleucids fled. I normally managed to kill a large number of enemies by going full speed after them, but it was *really* annoying.