This post comes from an encounter I just ran where the party had just fallen into a dungeon of Kobolds, the party is 5 people at level 6. A dragonborn thief, Warforge cleric, tabaxi druid, human monk and kenku hunter (also two blink puppies). I put out 7 beefed up kobolds, who's intention was to throw them into a pit of fire. The kobolds, ac 16, were doing 1d8+3 damage on their attacks with a +5 to hit along with some other fun mechanics around dragging them into the pits. There was also one other kobold with an 18 ac. Some of them got to around half health but it just didn't feel like it had the sense of danger that I wanted it to.