I think it’s a little weird.
In every other event, the leaderboard shows who most efficiently converted gems into points. You get points for spending sigils, and everyone gets the same amount of sigils. The leaders are never people who used only the free sigils. The real function of the leaderboard is to encourage competitive players to effectively bid gems in an auction against each other.
You don’t really spend gems or sigils to fight gnomes. You roll some dice every time you play an Explore match. Sometimes you get a gnome. That’s not a good basis for leaderboards. Someone who finds a way to play 1,000 Explore matches per hour might find 3 gnomes. Or they might find 6 gnomes. Or they might find 50.
So instead of encouraging players to spend money on gems, the only thing a Gnome leaderboard encourages players to spend is time. And if a lot of players found out the result of spending a 12-hour shift of Gems for an entire weekend was only 10 or 15 gnomes, it’d probably be worse for player sentiment than keeping the abysmal rate a secret.
So I don’t think it can be just a leaderboard. It needs all the other trappings of an event, including sigils and a shop. Or we could just leave it as-is and play the Gnome drinking game: take a shot every time you find a gnome and you win if at any point it’s illegal for you to drive.