One team varies from three to six people. Another has maybe 20.
The larger team definitely produces more intermediate artifacts than the smaller team. You could say there's more process in that team. But it's still not formalized as a methodology. The larger team mostly just muddles along. I'd actually prefer to organize the larger team's tools a little better, e.g. maintaining a single, sane VCS. Even if we did that, I wouldn't claim we're following a methodology. (By my definition, artifacts and tools do not a methodology make.)
Teams beyond a certain size seem to require some intermediate artifacts. (Bill Joy described an ideal-sized team to be the number of people who can sit comfortably around a dinner table: so 3-6 is fairly perfect for his definition.) It seems like small teams can just keep each other in sync with quick conversations. They seem to be able to keep the design and requirements in mind at all times. Maybe it's the scope of what they're trying to solve or maybe it's some residual overhead that larger teams create due to additional communication "friction". I'm not sure. It's interesting though.