My suggestion fastly described and quite small but in my opinion, it would be a noticeable improvement to our current system how Armor Class and To Hit is handled.

The idea is you have already a formula to calculate how high the miss chance of a certain monster against the players AC is and vice versa.
My Idea is to roll a d20 to see how high your damage is instead of only decide if it is a hit or a miss.
If you roll a 1 you still miss because I don't want to miss the chance to completely fail with a bad luck because I see it positive if you have an unpredictable situation you have to deal with sometimes. This increases the fun in DDO in my opinion.
But for all rolls from 2-20, I would handle it different from what we currently have.

So I make a small example who might show clearly what I want.
Your current Armor Class versus To Hit formula calculate for example a 50% miss chance.
Now you roll a d20 to see how much damage you do.
If you roll a 20 you do 50% damage (due to your miss chance) and an additional 45% bonus to your damage from the d20 roll and this means you do 72,5% of your damage.
If you roll a 2 you do 50% (due to the 50% miss chance) minus 45% from your low hit roll and this means you do 22,5% of your damage.

The positive effect of this change is that every Armor class and To Hit point matters.
The chance for peak damage that kills you is reduced and it is easier to give monsters higher DPS without making the game worse.
But the main benefit of this change is that the D20 is then always centered on the meridian of the miss chance and with this, the d20 is the central point of the Armor Class versus To Hit calculation.
The DPS is slightly decreased due to the remaining miss chance on the roll of a 1.
grazing hits are removed and you see no misses anymore besides you roll a 1, it is, of course, the question if you want this but I see this as tolerable.

It is hard to tell if the formula for the miss chance determination is well made but I think it is a working calculation.
With this addition, you basically need no physical resistance system in my opinion but it is still not bad to have this addition.