1. It wouldn't be the first quiz on JetPunk where typing a word gives you more than one answer. I think a few quiz takers like getting the "free" bonus.
2. The number for Nashville you have taken from the census uses a similar geographical grouping. The figure for Louisville from your quoted source is 616,261 - close to Nashville and more than some of the cities on your list.
For consistency with the premise of your quiz, I would respectfully request the inclusion of Louisville.
(Can't believe it took six years for anyone to make the joke! :) )