Superlatives were the order of the day back in the 19th century. Telling the crew that the USS Constitution was much better that British ships because of the type of wood used in her hull gave the crew confidence. You hear all kinds of stories about how strong American oak was, but face it, All oak wood falls within narrow hardness parameters for that type of wood. Also, American live oak was used only for structural parts of the hull, but not for planking. Planking was usually red or white oak. Europeans also grew and used live oak in their ships. As far as how many cannonballs were found, that begs the question, "How many got through?" I'm guessing the ratio doesn't differ between european and american ships. If the observation that French ships fired broadsides much farther away than the point-blank British volleys, the I would expect more holes punched through the French ships and less to the British ships. But to say that "American Oak" is superior to "European Oak" to the point that it actually makes a real difference is specious. Red oak grown in Europe has a slightly longer growing season and thus a narrower grain than red oak grown in America, making european red oak actually a little harder than american red oak, but the difference is negligible, it's still the same species of oak and has the same characteristics regardless of where it's grown.