Just finished a Normal Oda Domination campaign.

My observations:

Bow Kobayas and Trade Ships seem to be the most frequent ships in AI navies.

However I still encountered a fair number of Medium Bune and probably maxed out Fire Bomb Kobayas (I don't think I needed to recruit any FBK, I just captured them).

Wako fleets seemed to consist exclusively of Wako trade Ships. If I recruited 20 trade ships the entire game it was far too many.

To my utter astonishement, the Kitabatake captured the Black Ship.

My post RD vassals were more than willing to launch naval invasions. Several of them made atempts on Shikoku, and the Uesugi sucessfully conquered Hyuga, Higo, Satsuma and Osumi.

Auto-calc seems to favour BK a lot. I had to fight many naval battles because the AI considered my medium and sengoku bune inferior to bow kobayas. I don't remember if this was the case before the latest patch.