I forgot to mention.. Graal is a game, not a competition. From a business standpoint it would be beneficial to add a Daily leaderboard to encourage activity in the sparring community, and potentially help grow it. With over 3,000 people on at a time it's a shame to see less than 50 people in the Arena at any given time (Not including Guild Spar).
Off topic, but another idea I have would be to implement similar improvements to Guild Sparring leaderboards, as well as publicly show a Guild W:L.