Attack (and defense) rolls are now bell curved (rather than rand()%max damage. That means that rolls are much more likely to occur roughly in the mid range. This is an over simplification but a weapon with an attack of say 8 will typically roll a 3-ish. A weapon with an attack roll of 30 will roll around a 10 (still way better than 3 but not nearly as lethal.
If you're using a Bell curve i would rather expect a roll around 15-16 for a weapon with attack roll 30, assuming it can rolls between 1 and 30. That put aside, while you'll find me a huge fan of those tools, i am not impressed by how you use it. At all.
Here's the first reason : i'd like to point out that you can also have half a chance to obtain a roll between 15-16 if you add 14 to a D4 roll. My point is just this : On one hand you use a bell curve to reduce the randomness of your roll, while with the other you use an rocket-propelled variance which completely shots down your efforts to get more predictable results from your rolls.
Does this look like an intelligent point ? I hope i doesn't but i fear it does. Because it's still missing the most important mark : we're looking at one roll. While we ought to be looking is the random function resulting from all these combat rolls. And actually, it's the only thing worth looking at.
Here's roughly the idea, that's how it works right now :
-weapon and armor are of the same value there is more than half the chances to get "blocked" result. The higher that value is, the closer you get to half chances of getting blocked. It no longer resembles a gaussian distribution in any way, btw.
While weapon and armor are in the same area, getting more or less weapon and armor got a huge impact on the expected damage is tremendous.
If weapon value gets lower expected damages, are shot to nothingness.
If armor value gets lower the expected damage reduction from armor gets slightly less than armor value (translation : the difference between a lord's hammer expected damage on a defense 0 and a defense 5 is almost 5).
That the kind of figure we're looking at. Or we should be looking at. Now you tell me where you want to go, what edge do you want to give to technology/ranged weapon, what HP you want (because there's still the solution to gives units sky-high HP so that combats use so many rolls you get your bell curve back) rather than tell me "hey, i replaced my normal distribution RNG with gaussian RNG you'll see more mid range results"...
No, we're not.