At the end, the Vanguard surrendered, and the Dutch had 44% of their ships left. There were actually three substantial English ships left, surrendered, that could have been boarded and towed back to the Netherlands. They were the Vanguard, Rainbow, and the Prosperous of London. The last was the same ship that Michiel De Ruyter took in the first day of the real Battle of Portland. Sadly, it was later retaken by the English, as the Dutch position deteriorated.
My theory about what happened may be only relevant to Privateers Bounty, but it seems if the Dutch can stay in a single line, tack back and forth, keep the English at a distance, they can do well. If a battle devolves into a chase, the English will pick off the Dutch stragglers. The thing NOT to do is to sail the Dutch line into the middle of an English massed group of ships.