I re-read the Perrin Conventions recently. They are still way more complicated than I am looking for, but I did consider -- briefly -- turning initiative into Dex + approximate weapon length in feet. But really, I think it might be much easier to adapt the rudiments of a system I described for signature moves.
If a combatant opts to keep outside of an opponent's reach, add weapon length to Move for each side and compare. The side with the higher total can add +1 to an attack or 1 point to defense. A character with a higher Move can opt to retreat instead of attack, avoiding an opponent's blow; if the opponent chooses to pursue, roll a d6 and add Move, then compare to the retreating character's Move to see if the opponent can press the attack.