How well do the creatures in this combat encounter work together?
- No teamwork! The creatures barely even notice each other.
- Awful teamwork! The creatures don't have any unified plan of attack and barely communicate.
- Bad teamwork! The creatures have a poor plan, and/or poor communication.
- Basic teamwork! The creatures have a solid idea of what they're doing and can work together.
- Good teamwork! The creatures prioritize working as a group more than individual actions.
- Great teamwork! The creatures have actually practiced working together before.
- Excellent teamwork! The creatures intuitively know how best to assist their team members.
- Flawless teamwork! The 'creatures' are just different bodies run by the same intelligence.
Amusingly enough, robots, drones, constructs, and undead are really common RPG enemies that are found in both category one and category eight.
So, RPG player characters have a magical power that's very hard to work around: their players are all sitting around freely talking to each other. Essentially, anything one PC knows is effectively known by all PCs, unless the first PC wants to keep it secret or your GM is super strictly against metagaming. But NPC combat encounters have an even bigger power: they're all being driven by a single omnipotent intelligence a.k.a. the GM.
What this means is that both sides of a conflict can perform incredibly well coordinated maneuvers with impeccable consistency, despite one group being a handful of goblins with INT 3, and the other group being a bunch of level one PCs who've known each other for five minutes. Let's be real though, I love that. It's half the fun of the game!
If you're a GM looking to make your encounters stand out, however, one easy way is to change how they use teamwork. For example, have a bunch of conscripts or bandits might sit at category 3 on the above chart... but if they've got a big scary disgraced former knight leading them, that knight could push them up the scale to category 5. A group of mindless undead will act very differently to those exact same undead operating under the direct control of a master Lich.
You don't need to go to a lot of difficulty here. Just ask yourself something like "Would these kobolds/bandits have the tactical foresight to sacrifice warriors to lead the party into a trap"* every now & again when designing encounters. Keep a rough scale. Think about how one encounter might respond to the death of their captain by fleeing, but another might respond with berserk fury.
And then once you've figured out some cool tactical maneuvers, TPK everyone with a dozen CR 1/8 kobolds.
* I'd say the bandits would NOT, but the kobolds would for SURE.
* I'd say the bandits would NOT, but the kobolds would for SURE.