By 8/8 I presume you mean hit points. If so then, yes they will attack armies that have only 2 units, if they calculate they can win. I would not expect to put a 2 unit knight army in a position to be attacked though, unless I felt the job I gave them was important enough to risk the loss.
An early 2 unit sword army will get attacked, but you should not be getting killed as they should not have much on hand to kill it with at that point or you should not be sending it out.
Once you get to armies that are yellow and have 6 or more points, it is less clear. I routinely have 7 HP cav amries in the field with no risk of attack. That is if no bombers or not near a town that could bombard them with cat/treb/etc.
I try not to put 6 or less HP armies in harms way, but have at times, hoping they could not be reached or would be left alone. Red armies are always at risk. I do not recall a yellow army being attacked as long as it had 7HP and 3 defense or better.
The one caveat is the noaipatrol. I have seen the AI run into an army with units on goto moves and the army was parked in the path. Once they accidently run into a green army and drop it to red, it gets attacked and killed.
If you do not use noaipatrol, that will not happen. The noaipatrol was meant to let you not have to watch the AI wander in pointless paths. That led to barb issues. If you play without barbs then there is no reason to use the aipatrol. On massive maps it just adds to the IBT times.
I only rememebr clearly one aipatrol running into an army in all these years, so it is not a concern. GR and Rat use it and it is not been a factor. Well of late they are playing CCM anyway and it has no armies.
