Cover Them In Armor

Cover Them In Armor mod increases the chances of mobs (such as skeleton or zombie) will appear in armor. Also, each zombie will appear with a sword in the hand (from stone sword to diamond sword).

It is also worth noting that with some chance the enderman will be able to start a fight with you with a ranged attack, which has a 100% chance of hitting.

By the way, each pillager will appear with armor.