So I am now noticing the weaker city CS. Just had a beautiful 7 city start, and my front cities had good jungle screens, with walls and a cbowmen. Before, this was generally enough to stop aggressive AIs. Well not anymore! Shoshone and Vikings both came at me from different sides, with a combination of horse and swordsman. My cities couldn't hold and I lost them both. Looks like I'll have to rethink some of my power expansion in favor of more troops.