The very top mares are still few and far between but given how good the race programme is for them, more mares are staying in training so the likelyhood is that some more will continue to pop up.
Winning distances and the lbs per length scale for me aren’t an exact science as I would argue that Honeysuckle was value for far more than the actual official winning distances she beat Zanahiyr (4½L) and Sharjah (6½L) by in her two Champion Hurdles. Golden Ace is a good mare but clearly isn’t on the same level as a Honeysuckle or Lossiemouth as she requires things to go wrong with others in the big race in order to win.
Interestingly, I believe that the famed 2m Punchestown match chase race between Buck House (the then 2m Champion Chase winner) and the Gold Cup winner Dawn Run was specifically run at level weights so that Dawn Run didn’t have that advantage to draw on and as we know, Dawn Run won the race by 2½L.