I'm sorry that I killing your suggestion topic, but anyway, just want to point you why AC in Fallout is useless.
The problem AC is bad in Fallout (not FOnline only), because in D&D there's 1d20 system, not 1d100, devs of Fallout forgot to change AC from 1d20 to 1d100, making it x5 times useless.
But most D&Ds has a problem that low level characters usually spend hours to hit someone, because on low lvl thier attack rolls are low, so the fights mostly looks like 2 blind idiots trying to hit each other.
If you'll see the same AC system in any other D&D, like Fallout has, then you'll see moslty 0, 1, 2 and very rare 4 ACs. It won't affect 1d20 system much, especially when skills are from 0 to 300 and AC from 0 to 40 in the best way.
So AC from original D&D will make low weapon skills totally useless.
And opposite to your suggestion armor should give AC depening on its class. You getting expensive armor, so you should be more defended.
But, if they will transform AC from 1d20 to 1d100, AC will become useful, but
1) Then they also can make jacket->metal->CA to light->medium->heavy.
So two characters with low Agility (or natural AC) and with hight Aglity will have almost the same AC when wearing metal, and no difference if they will wear CA.
So if metal will have max natural AC bonus limited, but will have its own bonus high, it'll allow to prevent having characters with uber high AC, the same goes to CA.
It's like in bluesuit, your AG and perks giving your AC. It should be like AGx3, anyway bluesuit shouldn't give much protection, because you need to do nothing to get it and the most brave persons are usually in bluesuit, because they know that they have nothing to lose.
Jackets will have max AC bonus from 8 AG, so 24. And give like x3 more than it gives now, so 24 too. So max is 24+24=48 AC, if you have 8-10 AG.
Leather Armors 6 AG, so 18, and x3 times than it gives now, so 45. 45+18=63 AC, if you have 6-10 AG.
Metals 4 AG, -> 12, 30 itself, so 52 AC, if you have not less than 4 AG.
CA will only count 2 AG, so player with 1 AG will have only on 3 AC less than player with 10 or any other AG, when using CA. so 2 AG gives 6 AC, and CA itself 60 AC, so you'll have 66 AC.
Also about build that allows you to have 95% in the eyes from 50 hexes with .223 ammo and long ranged weapon to 10 AG guy in BA is...
I don't think you should have always 95% to hit. Making shot with 40%-50% will make fights a bit longer and armor will really save you because of AC.
Also what bad in it, if they will start to miss? Yes, they will lose more ammunition, so they will have to craft more... but also you'll live longer making fight more longer itself.
Bursters will deal very low damage on long range with such AC system because of lack of skill.
Snipers will not always hit thier target in the head or especially eye.
Even in short distance bursters won't always kill snipers, because they will need much more skill than they all have now, or else only few bullets will hit target.
Melee and Unarmed character will need to raise thier skill for more than 150%, because it's like SG EW and BG capped at 300%, while throwing melee and unarmed at 150%.
2) Just multiply AC modifiers from AG and armors, because for 1d100 hit system and 0-300 skills current AC is the same as 0-4 AC for any other D&D game, and these max possible 4 AC won't affect anything even on 1st character level.
