Hi captains (and hopefully Devs)
Time ago PB were modified to fit into one of three categories , trying to gain variety to the collection of ships we use on those battles.
While it is true that these battles become a bit more entertaining, the number of variants are equally limited, as practically everyone tends to use the same ship - allegedly the most more useful in each category, 1st rates for RC, 4th (inger) for Deep ports and mercury for Shallows - so in practice only 5 or 6 ships