if the actions of the players don't change anything then that's the definition of no agency. Not saying every action should make a measureable change in the game world but it should make a measurable change in the pond they play in.In this case, Alex is a very independent gamer....and he does not like the other two players at all. So he keeps apart and independent , but still plays the game with them. Billy goes to the full Lone Wolf extreme of ignoring all the players...though he does the "copy Alex" thing. Billy will make a big deal that is "not" coping Alex, and that he is just randomly picking the same things as him every time.
As they are "Summer Mash up" games....they are far from perfect.
This is the big split between me and the Gaming Collective. I don't think any and every action a player randomly has a character randomly take can and should alter game reality.
A lot of my requirements are fairly basic: Pay Attention, Focus, Engage and use Common Sense.
HUmmm....possible.
They might be mixing Easy Button play with Player Agency. Most of the players are used to the "no effort easy button" play where their Fan DM just alters game reality and rolls out the red carpet no matter what they do. I'm nothing like that.
I will say I've never had a table with players that didn't like each other that didn't blow up at some point. Usually it starts with a table of people that get along great then someone brings a friend or a few or a couple bring friends and then the arguments or in game player disfunction starts. It's not a common thing but I've seen it and It makes me very uncomfortable running a game with players that don't want to be in the same room with each other. That all by itself can blow up the game even if everyone is staying in thier own lanes. Some people just cant sit in a room with people they don't like and enjoy themselves. Is it possible that is your issue and no one wants to admit they are the bad guys that can't play nice with people they don't like.