A wizard has just killed a group of heavily armored fighters with great weapons. He uses Animate Dead on the bodies. The spell reads as:
This spell creates an undead servant. Choose a pile of bones or a corpse of a Medium or Small humanoid within range. Your spell imbues the target with a foul mimicry of life, animating it as an undead creature. The target becomes a skeleton if you chose bones or a zombie if you chose a corpse (the DM has the creature's game statistics).
So from the wording of the spell, these corpses would turn into zombies, as in you are making that body move again. You aren't mashing up the body into a stew and pouring out a new zombie, they're identical, still wearing the armor. Do zombies wearing plate have an AC of 18 instead of 8?
In the section on zombies in the MM, they have the Slam melee weapon attack, which does 1d6+1. The description section for zombies does read:
A zombie armed with a weapon uses it, but the zombie won't retrieve a dropped weapon or other tool until told to do so.
The wizard tells the zombies to pick up their greatswords. Does wielding a greatsword override the Slam attack and they now do 2d6+1?
Armor and weapons require proficiency. The people using the equipment were proficient in them, but are the zombies proficient? Does a zombie have disadvantage because it isn't proficient with this gear? I am certain that the zombie would have reduced speed because it only has a strength of 13, not the required 15 for plate.
Finally, do the implications of this extend to other types of undead? Can the wizard use Create Undead and make ghouls that wear armor?