I am not a big sports fan and I do not understand it very well, but International Professional Tennis has a Seeding System and I wonder if there is a way that to rise in at least in the Duellist League Table you have to fight players only say, 10 places above you in the League in order to count.
e.g. You are 54th in League so you can attack to receive points only those 10 (or maybe 20) people above you. if you beat them, you get half the points difference and they lose half the points difference. Likewise, you at 54th can be attacked to win points by anyone up to position 20 in the League.
It follows that those at the very top of the League can only get further up the league by duelling those above them.. Of course, the temptation for anyone at the top would be to refuse to duel, thereby attempting to retain their position by default, but if a Duellist in say, the top 50 who is online declines a duel, they lose a certain number of points (lets say the number is Z) up to a maximum of say 5 times Z in any 24 hour period.
This would not work in the Arena since you have too many variables and to be honest, so often there might only be a pool of 6 to 10 players signing up for arena.
If one is an also-ran like me bouncing along at the bottom, I would play it all more if I knew I would not be 'of interest' to anyone in the top levels of the game. I get approached a lot by people I know to be high up in the League tables at the moment, knowing they can beat me easily. they are only doing it to get easy points. But if we both knew niether player would gain or lose points, I could then perhaps improve my own pvp skills by having a Mentor and me being a sort of Apprentice. I think it could work well for all those people who want to improve with no impact upon their rankings.
I appreciate these are not solid suggestions or might not even be practical but maybe the 300 point difference could be reduced from 300 to say, 100 on a trial basis for December ?