It's been a while since my wall was attacked, but it happened today. So I wanted to point out some important observations about what transpired
First... I noticed my wall was being attacked, I took a look at my hospital, I figured there would be a ton of troops to start healing up. A Unit of Archers? But it's been successfully hit 3 times so far and I have one of the highest ranking's in my city, what is going on?
Another level 40 player was defending me, but he is lower rated player?
Here are the stats for the 'wall' swords my wall called in for using
Legionnaire rating 829 Health 60.0k Attack 55565
Here are the stats on my 'Wall' Swords there where not used
Legionnaire rating 829 Health 65.40k Attack 61100
Despite my units having way better stats, it still opted to pull from someone defending me likely because they hold the same rating. This however is seriously crippling my defense. A unit of 24 swords of mine have a combined have an extra 129k hit points. I'm sure they would have made a better deference then the ones used. Key point here it to be aware of who it is defending you. Unless they have troops better than your's, there not doing your wall any favors.