Nifft
Penguin Herder
That solves a bunch of other problems (like the ballooning discrepancy between weakest defense and strongest defense) but requires re-working most critters.Personally, I'm all for stats not increasing with level, ever, no enhancement bonuses, and you can get up to 4 differentiation (light armor +1, heavy armor +2, shield), but then we're talking about 5e for some of that, and pure houserules for some other.
Also, players like when numbers go up, so you'd need to find some other way to give them that perk.
Cheers, -- N