In a recent game on Noble, I let my military languish while I teched up to Rifles/Military Tradition. I was just a few turns away from Military Tradition when an AI on another continent to the north DoW'ed me. His first sea invasion happened before I could get enough Frigates up north to stop him (most of my production cities were in the south), and I lost a single city. I quickly retook it -- Cavalry vs. Macemen is a joke -- and started destroying his future invasions with my Frigates. As I was attacking his sea invasion stacks, though, I noticed something funny. He was escorting his Galleons (strength 4) with Caravels (strength 3). Both his Galleons and the Caravels had Combat I promotions and nothing else, so by my understanding of the combat mechanics, the Galleons should have been picked to defend the stack. But whenever I attacked with my Frigates, I'd kill a Caravel, not a Galleon -- and often one or two Galleons would slip through to drop their troops on my coast, where my Cavalry rapid-response force would quickly mop them up. Not that I'm complaining about the free XP for my Cavalry... but why were the AI's Caravels picked to defend his ship stack instead of the higher-strength Galleons? Is it because the Galleons count as "transport ships" and thus won't defend the stack as long as they have any escorts? But if that's the case, why wouldn't Caravels also count as "transport ships" since they have a cargo capacity of 1? There's something I don't yet understand about the game mechanics here. Any enlightenment would be appreciated. The AI was Mehmed II of the Ottoman empire, by the way -- Exp/Org with the Janissary as his UU, so his ships were perfectly standard units as far as I know.