AI and Embarking - Still can't do it well?

I should disclose that I haven't played THAT much BNW yet, but the AI thus far seems still unable to mount decent cross-ocean attacks (or any body of water that is). This makes all island/archipelago maps a bit strange and easy to fend off stronger AI's.

Has anyone seen this and can comment on their experiences?

I've seen a number of amphibious invasions involving infantry, artillery and protected by boats. They're typically smaller than they should be (3 inf + 2 art + assorted boats on a standard map I've seen relatively regularly) although they seem to be reasonably well executed and manage to maintain some kind of acceptable formation, even through narrow straits.

However, I didn't see any of that until the AI had cannons and rifles. Whether they can do something similar in the pre-Industrial era I don't know.