[Edi]

Originally posted by Cheezeninja:
Every time I have set MY units to attack rear they actually attack the rear section of the frontmost group of units. They dont actually jump back to commanders, except occasionally when there is a large body of troops there as well. And i have NEVER seen my troops actively seek out commanders fromt the start. Unlike Ashen Angels and other nasties, who invariably seem to attempt immediate evisceration of commanders.

IIRC, units with "attack rear" orders must make a morale check or something like that every time they pass a stack, and if they fail, they will attack the rearmost units of that stack. On a battlefield with e.g. 7 stacks of AI units, they need to pass all of those checks if they are to attack the very rearmost units (typically the commanders). Failure to pass the check causes the units to attack the rear of the closest enemy stack. Every unit in a stack must make the check separately, so this is why you sometimes see some cavalry units breaking ranks from their squad and go after something they should leave alone.

Looks like the AI got very lucky with the harpies. Of course, if you had all of your HCs in a single stack and had just them and the Nataraja, the harpies only needed to succeed once to get at your astrologers. Having several squads mitigates the problem with flyers that attack rear.

Edi