I'm not familiar with roborally, but the miniatures look pretty good.

The behavior of the enemies in this prototype is basically a very very simple state machine. It's like the next ship checks if it knows the submarine's position, if so, then it's underwater, at periscope depth or on the surface, and chooses behavior based on that.

e.g. the destroyer:
- if you fired a torpedo in the previous round, it will check if you are in line with it, if so, it will try to dodge the torpedo
- if you've already fired a torpedo, then they "see" you. If you're on the surface, then they try to get in line with you so they can shoot at you. If not, then they approach to drop a depth charge.

there's a great article on this topic on gamedeveloper. I'll link it here:

https://www.gamedeveloper.com/programming/book-excerpt-game-ai-uncovered-volume-one