So how do you win, when running a Privateers Bounty scenario? It is almost a separate issue from whether you are controlling the Dutch or English, although the English have great advantages, if you are in control against an autonomous Dutch fleet. If you have the nerve, you can "break the Dutch line", although, typically, they will just be spread out, not in a strict line ahead.
In any case, due to peculiarities about how Privateers Bounty simulates sailing ships, your fleet is going to spread out, dispite having a single line formation set, with close spacing. The problem is that the ships have different speeds and turning ability. That alone will cause ships to spread out, especially as you maneuver your fleet.
You can control individual ships, but I find that is only feasible with small numbers. When 40-ship fleets, you must maneuver them as a group, just to be able to exercise the positive control needed to reduce your losses and to inflict the maximum losses on the enemy. I prefer to tack back and forth, always turing downwind, if possible. It is possible, if you have sufficient momentum, to turn past the wind, but it is too easy to get caught, bow on, into the wind. If you do, you have big trouble. The thing to do is to immediately turn your helm 60-90 degrees, and hope for the best.