OTOH, if they could do this estimate and leave you be everybody would be running from you most all the time. In mid-late game anyway.
I have noted on many occasions that weaker than me parties try to run away(or ransom themselves) from battle, sometimes even Bold Privateers(they only run mind you). The latter even occasionally display instinct of self-preservation in harbour battles. This is an improvement from earlier behaviour.
Still, the simplest way to rectify that and increase immersion would be making common pirates neutral to pirate player. Even nicer would be to have a possibility to befriend them like the smugglers.
Rgds,
Oldtimer