I can understand that to a degree as I aid everyone however when I have someone that continually attackes me I quit aiding that individual.In my main city I only attack and plunder those neighbors that don't aid me. It serves a couple of purposes. First, they'll start aiding me or even better send me a friend request. Second, it's how I get my previous generation goods.
I aid daily, so I make a pretty good friend. I also make a reliably "bad neighbor". It's in all in my profile. My choice would be for people to aid me.
If I am attacking through the neighborhood for quests/dc's/HC/etc. but not plundering and I come across a 1 anything defense I WILL go out of my way to plunder anything I can. So by trying to lock out the guy who's been plundering (and probably still will), you've now just added another plunderer to your city. Smart move!!!leave 1 spearman so they get very few battle points.