At this point I believe that Elemental combat would have been far better if it had taken some hints from tabletop miniature games which are designed to have simple rules without needing a lot of calculations on behalf of the players. Things could (and still can) be more simple while still being deep. It's too probably late now for such a major modification to the core rules, but I hope that something like the following system could be implemented as a mod. Please let me know if you are aware of any hardcoded things that would stop such a mod.
First of all, all units have only 1 HP. Champions have more depending on their Constitution. This makes sense because it's unlikely that a unit can take more than a well placed blow before being out of the battle (not necessarily dead but given that one damaged arm is enough to make you useless, that's enough). Verily, I hate "Hit Points" in games because I find them so unrealistic. They're more like "luck points" than anything else, for it makes no sense that anyone could possibly be combat worthy with more than one glancing arrow in them.
Now how combat works is going to be similar to the true and tested Warhammer rules and other games which play in similar ways.
Units have the following statistics
Combat skill (CS): Based on DEX and experience, which defines how skilled the unit is on landing or avoiding a succesful blow on their opponent.
Damage (DAM): Based on STR and weapon. It defines how likely a landed hit is to bypass the armor of the opponent.
Resilience (RES): Based on CON and armor. It defines how likely a hit is to be shrugged off.
Now the way an attack works should be obvious already:
Lets take the scenario of one on one battle.
First we compare the two unit's combat skill. If they are of equal skill in battle, then the chance of one landing a sold blow on the other would be 50%. So we make a random roll to see if they hit. In case their combat skill is unequal, the obviously the more skilled one has an advantage. If we say that most units start with a CS of 10, then we can have a simple systems as so.
normalized d40 chance of landing a blow = 20 - Attacking CS + Defending CS
So this means that if the attacker has a CS of 12, while the defender has a CS of 10, then your d40 roll would need to roll 18 or higher to hit. The d40 roll could also be normalized so that it's not as random. The easiest way it to roll 3d40 and keep the middle roll. This ensures that the most common results would be in the middle, therefore making it more unlikely that very skilled warriors will just get hosed by bad luck. This also means that if there's a difference of more than 20 points in CS, it's an automatic attack/defence (the game should warn you before attacking in this case)
Now once you land the blow, another calculation takes place which is to see if the blow penetrates one's armor. This goes like this
normalized d20 chance of wounding the opponent = 10 - DAM + RES
So this means that if the attacker has a DAM of 8, while the defender has an armor of 10, then your d20 roll would need 12 or more to wound. The scale is smaller because DAM and RES are not directly correlated to STR and CON respectively and items do not add so significant amounts of dam and armor. This does mean that if someone has more than a difference of 10, it's an automatic success. So only your very heavy hitting heroes should be able to take down that dragon.
If one gets hit and wounded, they lose 1 hp. That's it. Since most units have only 1 hp anyway, it means they will die. This means that battles will not be a protracted smack fest between two HP sponges but you may get equally skilled opponents unable to land a blow.
This is the basic form of combat. Squad combat will be similar but rather than making just one attack roll, you will make multiple. For each attacking member of the squad, you will roll one Attack. For each succesful Attack roll, you will roll one Damage roll. For each succesful damage roll, the defender will lose 1 HP. Obviously if it's a defending squad, each succesful wound will kill one of their members.
Now how will these numbers be modified? By the most intuitive way of course.
Lets say that most units start at a CS equal to their DEX. For Champions, that's all you need, since with leveling you can choose to increase their DEX directly. For normal units, each level up will also add one or perhaps two points to their CS. Some weapons such as daggers might be able to add points to your CS directly, or only when you're attacking. Shields will obviously add to your CS when defending. Magic items might increase it directly or via a percentage.
Your DAM will be calculated similar to how it is now. Weapon damage increased by a percentage based on your STR (STR*10 % i.e. a STR of 12 will give you a 20% increase in weapon damage).
Your RES will be calculated in a similar way to DAM but with CON and Armor. Total Armor value modified by a percentage based on your CON.
So this is a very basic rule for combat, but it can easily be extended to magic damage (no Attack required and DAM equal to spell dmg modified by INT and shards). Ranged attacks will work similarly but you don't use your opponent's CS to reduce your attack but it's reduced by the range. Yes, skilled swordsmen are not very capable of doding arrows unfortunately. Shields however would count double.
So what do you think? I'm not doing to be doing anything until the initial patching iterations have calmed down a bit of course, but is such a mod even possible with the current modding tools we have?