Japan gave you his entire empire? That's not even fun, is it???

Has anyone noticed the AI using its non-combat units tactically in battle? I made a deal with one AI to go to war against another (I love the 10 turns to prepare option, btw) and we were falling over each other to take our victim's cities. My asshole ally brought up settlers and workers to block me from the coup de gras attack and he ended up taking the prize city after I did the hard work of beating it down with my crossbowmen. I was impressed.