Player Parties and monster balancing?

So i unlocked player grouping/parties and decided to give it a shot but i am not sure how you are meant to balance your MMO for this?

As far as i can tell the players wont allways group up and wont allways be in a group of 4 so monsters based on a single player will be stomped out immidiately and any monsters you make for a 4 person party will be attacked by solo players and lower group amounts and then they will complain that they keep dying?

Unless players are smarter than i give them credit for and make sure they group up enough to take strong monsters down? just want to know other peoples thoughts on this.

Feels like a group of 2 would take on a one-level-higher monster, and a group of 4 would take on a two-levels-higher monster. Or they just use grouping to die less, and maybe that’s fine!

As far as im aware there isnt a “this MMO is too easy” negative thought in the game but i do like to have my players at least have a difficult time with monsters.

there is a “monsters are too easy” neg thought

also id have my monsters high hp and low dps so it’d take 1 person a very long time, or 4 people a decent amount of time to kill

The “too easy” response seems to mainly be about monsters dying too fast. If you give players very powerful defensive abilities, they don’t seem to mind the fact that they almost never die.