Armor Proficency Medium is a very powerful feature for a caster no question. But Armor and weapon proficencys do nothing for fighters barbarians rangers and paladins as they already have these proficencys. Previously Shield Dwarves traded off stat bonuses for the armor profiency which balanced them as casters and melee you got great proficencys for a caster but great stats for melee but you lost out stats as a caster.
In my opinion Shield Dwarves, Humans and Half Elves were better balanced against the other races keeping there stats the way they were. I would not even give the choice for shield dwarves and half elves as they were balanced the way they were against the changes for tashas give something to get something. The armor proficencys make them strong casters but having better stats for melee str class builds.
On the other Side of the spectrum humans vs varient humans comes into question +6 all stats is strong if you want to multiclass and ok for classes that want 3 different stats higher or 4 but not as good as some other racial features so its ok it made them kind of middle of the road for a lot of classes.
Varient Human I think just sits on par while the feat is strong and creates versitile options for human to make the strength the versitility. But varient human was just versitile tashas makes the other races as good if not better than varient humans depending how you want to build. +5 ft movement dark vision resistance and proficencys and a +1 stat vs a skill and a feat of your choice. (Comparing wood elf to human as an example here).
