Quote Originally Posted by EatYerGreens
In STW, I'd occasionally include unit remnants of less than 5 men in a province when overwhelming numbers were across the border, so they could be hidden in trees a long way away from my main force and play for time at the end of what, by rights, ought to be a heavy defeat. The AI had to scour the map, looking for them and often failed to do so, allowing me one more season to redeploy and meet the follow-up attack.

If anything, the fact that you can't use this exploit any more is an actual improvement to the game. There's now more of an incentive to build castles in frontline provinces and retreat to them, when outnumbered, which is the proper way to buy the time required to redeploy troops to where they are needed.
You still can use this bug if you have a decent unit with exceptional morale. As the Almos I parked a badly mauled unit of faris at the edge of a map during a sandstorm while vastly numerically superior enemy units paraded past me. When their units got relatively close and my unit's fatigue bar was very low I got the flashing flag too, but it went away when the fatigue bar went up and the enemy unit moved further off. My whole force had been routed but the 2 units I had saved and hid away were skirmishing units I used to screw over enemy reinforments and disrupt their unit migration to my strong point (so their units don't all arrive on my front lines at the same time). These units were far away from my routing units when all hell broke loose and might have missed the demoralising effects.