Honestly, if I was going to 'simplify' armor, it would just be to flavor text. Thus -
Light Armor - 12+Dex, 15 G.P.
Medium Armor - 14+Dex (max +2), Disadvantage on Stealth, STR 13 min., 50 G.P.
Heavy Armor - 17 AC, Disadvantage on Stealth, STR 15 min., 400 G.P.
This way you stay within bounded...