The flags and be swapped out because of magnets or by simply pulling them off the mast heads and then she will be English or some other flag as needed.
The second ship is an English frigate that I have decided to use the "bark tan" or red sails. These were common in the far east so this ship may have recently returned from service in the Indian Ocean or East Indies.
The affect is quite striking, and she looks very fine. She will make a good pirate if I ever need one.
Her flags can also be swapped out for another letting me field them as American's, French or others as needed.