A rebalance of the AR value of nearly every armor sets of Vanilla, TR Data and OAAB Data.
Basically, 1144 references were modified. It was done following my personnal view and preferences, some logic and coherence and taking into account a mod I use that allows Unarmored, Light Armor and Medium Armor to increase dodge chance of the player.

I cant list everything, so here the global logic :

• Spreading more evenly the AR of each armor class between the min and max value available. This is to avoid big jump of AR during progression.
• Heavy Armor benefits from the biggest increase : Iron armor went from 10 to 20, steel from 15 to 30, dwemer from 20 to 50, daedric from 80 to 100. Even the lowest level heavy armor should offer most protection than most of the light armors, and only the best medium armors should somewhat compete with good heavy armors. For their weight category, it should be no brainer that they provide better protection.
• Medium Armor are overall better, whith a better spreading of the AR value : nordic mail is left untouched at 10, Imperial went from 12 to 20, bonemold went from 16 to 25/30 (depend of some set), orchish went from 30 to 50 and Indoril/Adamantium went from 45 and 40 to 60. Medium was objectively the worst armor type in the base game. They now all provides a good amount of AR comparatively to their weight.
• Light Armor was globally nerfed with better spread AR : Most cloth, fur and necth were left untouched at around 5-10, Chitin form 10 to 12, Bug armor from 12 to 15, wolf from 15 to 20, dark brotherhood from 30 to 20, morag tong from 12 to 25, and glass from 50 to 30. It is mostly a nerf. It is based on personal preferences and as I said, I used a mod that allow light armor to give a dodging bonus. The glass armor was just excessive for its category, its sole existence outperforming nearly the whole medium armor class. The gap between glass armor and the other was also too great.
  

I only gave some exemples. All artifact based on a generic version had their AR changed accordingly.
Some very powerfull artefact that already had AR of ~100 were boosted up to 150.


As a reminder, here how armors works in Morrowind, using info from the UESP :

AR is calculated this way : BaseAR * ( ArmorSkill / 30 ). The value is then divide proportionnaly among the body parts that are covered wher chest represent 30% of the total, each glove 5% and each other 10%.

So in this mod, with 30 Heavy Armor Skill with a full daedric set you have 100 AR, and at a skill of 100 you have 333 (in vanilla it would have been 80 and 266).

How does AR impact incoming damages :
Min(1 + Target's Armor Rating / Damage ; 4)
A character with an Armor Rating of 33 that is hit by an attack inflicting 50 damage; 1 + 33 / 50 = 1.66, which is less than 4 and thus can be used in the equation. The 50 damage would divided by 1.66, resulting in the character losing ~30 health (a damage reduction of 40%). Alternatively, an attack that instead inflicts 100 damage would instead be divided by 1.33 (1 + 33 / 100 = 1.33), resulting in a loss of ~75 health or a damage reduction of only 25%. Damage cannot be reduced to less than 25% of the original amount.

Soooo, what it means for this mod : The impact is less noticeable for high-end heavy and medium armor, but significant for low-tier heavy armor and mid-tier medium armor. Players and NPCs wearing heavy and medium armor should have an easier time in combat, compensating for the weight and the need to repair their armor more often. I understand if you feel it's a general nerf to light armor, because it is. But as I said, I made it followinf my personal taste and mod list.

The mod was cleaned with Morrowind enchanted editor.

Futur of this
This mod only changes AR, but I really wonder if it should also affect durability, enchant value, price, and (somewhat) weight. I'll see what people think about that.

Installation
Put the .esp in your Data Files directory and activate the plugin in your launcher.

Compatibility

Oviously highly incompatible with anything that touches armors. I recommed to merge with your modlist.

I also included a patch for every armor mods I personally use :

Bonemold Armor (same change as vanilla bonemold, as it is a .esp replacer of the base bonemold armor)
Cammona Tong Chitin Armor (from AR 30 to 15)
Ceremonial Adamantium Armor (from AR 50 to 60)
Concept Art Daedric Helmets (from AR 70/75 to 100/110)
Daggerlad (from AR 6 to 15)
Dragonbone Armor (Some pieces AR equalized from 90 to 100, Aryon Glass cuirass AR from 50 to 30)
Hammerfel Ansei Warrior Armour (light armor, from AR 55 to 32)
Heavy Chitin Armor (from AR 40 to 25)
Indoril Ronin (medium armor, from AR 40 to 55)
Morag Ton Equipment Diversity (from AR range of 16-35 to range 20-25)
Morag Tong Polished (Grand Master AR from 45 to 30, Normal Morag Tong from AR 30 to 25, some left at AR 25 or 16)
Netch Scout Helm (from AR 18 to 5)
Redoran War Armor and Sathil Mercenary Equipment (Redoran War Bonemold (medium armor) AR from 15-17 to 27 and Sathil Mercenary Armor (Light) AR from 14 to 16)
Sathil Mercenary and Redoran War Armor V3 (same as above)
Redoran Master Armor (medium, from AR 45 to 35)
SM Morag Tong Armor (from AR 12 to 25)
Complete Duke's Guard Silver by Ruffin Vangarr (heavy, from AR 20 to 35)
Web of Mephala (all light armors : Mephala, from AR 65 to 40, making it the best light armor in my setting; normal Morag Tong AR from 12 to 20, and Elite AR from 30 to 25)
Telvanni Armors - Slavers and Wizards (every bonemold AR from 16-18 to 25-27, one unique Iron gauntlet from 10 to 20)
Telvanni Dust Adept (AR equilized from 10 to 5)
Base mod is always required. Activate them after the base mod.