Simple question that I would like confirmed: What is the difference between selecting "Posse Up" and "Free Roam" on the main menu? At first I thought there were 2 different types of servers: one where players were all thrown into random posses, and another where people spawned on their own and could create posses if they wished. If a temporary "open" posse was created in Free Roam, I thought only players on the same server would be able to join, probably from the D-pad menu. However, I am now convinced that there is actually only one kind of server: Free Roam, and if you select "Posse Up" from the main menu, you are auto-joined into a random temporary open posse that someone already created in Free Roam.
For any newbies Googling this topic, please confirm that I am right?