Also we do not need categories of weapons and armor.
all weapons can be in one category and all can be proficient with all weapons.
Martial performance can be measured via:
Fighting styles, Extra attack(s), attack riders(sneak attack, smite, various class bonuses), abilities that enable usage of Bonus action for extra attack, feats that augment attacks(SS, HWM, PAM, CE, Sentinel, Crusher, Piercer, Slasher, etc), basic investment in STR or DEX,
Armor can be measured only in min STR required.
No need for class proficiencies, or capping dex or having Stealth or other penalties.
Armors:
AC 11, min STR 10
AC 12, min STR 12
AC 13, min STR 14
AC 14, min STR 16
AC 15, min STR 18
AC 16, min STR 20
AC 17, min STR 22
small shield(buckler), +1 AC, min STR 10
shield, +2 AC, min STR 14
Some races(dwarves) can have cultural armor training in a way that their STR is 2pts higher for calculating what armor you can use.
Same would be for some classes/subclasses:
I.E. fighter and paladins, and some subclasses of other classes can calculate their STR 2pts higher for armors.
Not having min STR for the armor you are using would inflict disadvantages on all attack rolls, not being able to concentrate on spells and having all targets of your spells auto-succeed on their saving throws and having disadvantage on all STR and DEX saves and checks.