Recently I jumped into a battle where a Swedish NPC Navy Brig was attacked by 3 brits (2x lynx and a cutter). I wish that I could have "told the AI" to focus fire one of the damaged lynx, but it seemed the AI shifted focus between the three enemies, dealing equal damage to them all (my observation - could be wrong).
Being the only human player on my team, maybe, just maybe I should have been able to give a few simple commands to my NPC ally. Maybe there is something like this implemented already, and I haven't been able to figure it out yet. I am still in the Lynx, since I can only play a few hours during a week.