Is it me or is it them?

This is what has been happening at the end of recess each day. I come down to pick up my kids and they are, basically, in line. They are talking, they might be in two rows like they're supposed to be, they might not, but they're all there, and we have our class ball, so I just start walking them back up to the building. As I walk away with my class, I see the other classes. Their teachers are waiting for them to be in line order or to be in a straight line. They have timers, they have signals, they are doing what I have been doing for years: making sure the kids are following the prcoedures for lining up.
I am doing none of this. I don't need them to be in line order because they seem to be able to walk with their friends and not talk once they're in the building. I don't need them to be in straight rows because they seem to be able to stay together and keep up in whatever formation they happen to be in. They seem to have this lining up and walking in to the building thing down.
But the thing is, I can't figure out if it's me, or if it's them. Here's what I notice. This year, no one is still playing after the bell rings so we don't have to wait for them to line up. Everyone seems to be there by the time I get there. Second, we don't seem to have the drama at the end of recess that we used to before. No one is coming to me with hurt feelings that I need to deal with which keeps us from walking in. So part of me thinks that it's this class- that I got lucky this year. For whatever reason, I got a class full of kids who are responding to the systems we have set up for them.
But then I look at the classes that are still on the yard. And none of their kids are still playing after the bell rings. And I don't see any drama or tears keeping them from walking, I just see their teachers waiting for them to line up in the correct way. So I can't figure it out: is it that my class is really well behaved? Or is it that I don't need them to have such controlled behavior?
It's easy for me to say "If they're all here, we start walking. I don't need them to be in line order or straight" because this class is all here, keeps up with each other, and stops talking when we get in the building. I wonder if I could do this if we had kids who didn't keep up with the group.
But now that I think about it, I realize that we do have stragglers, and that we wait for them when we get upstairs. But I don't mind that this year. I feel like they're part of our class and so of course we wait for them. And we have had drama, a couple of times, and we've been late because of it. But lining up straight or being in line order wouldn't fix that. Also, the class has had to wait while kids talk to each other about what happened at recess but no one has complained about it and to me, it's not such a big deal that we're late. We'll get there when we get there. It's more important that the kids deal with what just happened than that we get to where we're going on time.
Of course, it's only the second week and we don't have any people waiting for us right after recess so I don't feel as much pressure to be on time. Still, I wonder if it's me, but I worry that it's them. I worry that someone is going to start showing their true colors soon enough and that I'm going to start going back to those controlling rules again...