UngeheuerLich
Legend
Yeah, honestly, if I was designing 5e I'd just make the AC for heavy armor a bit better. I mean, DEX is a slightly better option than STR, but if the STR fighter could also have an AC 3 points higher than the DEX fighter when in plate armor or something, well you'd have to really think that one through! I mean, DEX would still be a perfectly viable option (and maybe its 2 points higher AC where the sweet spot is, I'm not sure). I mean, it appears that HISTORICALLY the later forms of armor of the early 15th Century were a LOT better than even mail, forcing the employment of a whole specialized set of weapons to defeat them, and obviating the need for a shield. I think certain these 'full plate' type armors could justifiably move up an AC slot or two!
I'd probably raise AC from Heavy and medium Armor uniformly by 1 point.
Right now, medium armor is only woth it at low levels, at high levels it is worse than loght armor, because either you have lower AC or a stealth penalty.
So chain shirt would be 14+dex (max 2), chain mail would be 17.
Maybe for heavy armor I would leave chain mail at 16 and just add an extra armor that is 9 AC for 17 Str.