I think the parameters are just right as they are. Right now, you have to be at ~60% of the effort credit of the leader. When all effort and promises are equal, that works out to about 2 full prestige grades; meaning that a C+ team can challenge an A+ team for a recruit and be on the cusp of getting in signing range, depending on preferences. Sometimes he'll be locked out at moderate, sometimes he'll get up to something like a one-in-four-or-five chance.
The only thing that should definitely change is removing the percentages after the fact. At this point, I think we all have a pretty good idea of how the system works, and how to put yourself in the best position to compete for recruits. Showing the percentages only serves to sow resentment.
If you want to eliminate the "high" category, fine. But then you won't know anything at all about your chances relative to the leader. I would think that introduces a whole new set of frustrations. I'll adjust either way. Just don't narrow the parameters, because the recruiting game needs to stay competitive for those top recruits. Minnesota needs to be able to compete with Michigan State for recruits, and win them once in a while, even the ones MSU really wants.