Just completed a Maratha campaign, and I'm now going back to jolly ol' England for another grand campaign, which means I need to really focus on my naval trade. I am trying to figure out the optimal number of NON-TRADE ships I should be putting on each individual trade node so they deter pirate attacks. I am aware a stack of 1 Indiaman and 2 brigs is not going to deter a European fleet, but I'm more concerned about constant pirates raids and want to minimize the necessity of sending in a local fleet long AFTER the pirates had destroyed the trade fleet.
Has anyone found a "Golden Ratio" of ships where pirates stop attacking a node and the costs of maintaining the node fleet do not outweigh the profits from the node? And what types of ships are most cost effective to put on the node?