I don’t know that sloops were the fastest ships. The amount of sail and the length of the ship at the water line play an important part in speed for a sailing ship. Not all ships even of the same class traveled at the same speed. But in the game I am sure they will.

The optimum hull length was about 200 feet at the water line. Smaller and larger ships did not perform quite as well. The rule of thumb was 1 to 4 beam to width but slightly narrower gave a slight speed advantage.

What all of this means is the Frigates were about the fastest of the war ships of the time. Smaller ships though could sail closer to the wind can could escape usually by sailing up wind.

The top speed for the fastest of these ships was about 14.5 knots. Most could not achieve that though and sailed a knot or even two below that speed.

One famous battle was between USS Constellation and L'Insurgente, noted for being the fastest ship in the French navy. The Connie won with the French ship trying to run away. (Watch out for the American Frigates) L'Insurgente was taken prize and returned to the United States.

Later Clippers we know were faster with the record being about 22 knots but they carried much more sail. Cuty Sark is said to have a top speed of 17.15 knots. USS Constitution is more than 200 years old and not in prime shape but her current speed is listed at 13 knots.