Can't you just have the same campaign setting but with each group carving their own history? Everyone that uses any campaign setting is sure to run it differently and have different outcomes. To keep track of the changes that each group has made, use a campaign journal to track their story. If you have a Bard or Scholar in the group, have them write the journal themselves for a little extra RP XP.
In my own campaign world, I use the same starting point and plot hook for every group. I like to see how different groups develop the same story. I have had groups that aren't very original and mostly follow the plot, while others find interesting ways to solve problems. For instance, my common start point is the group is being paid to scout the enemy army. The boring groups (3 in total) do just that, keeping track and just making their reports. One group decided to set fire to the forest as the enemy army marched through (Alchemist Fire suspened with timed candles to start the fires). Another group damned a river and then burst dam as the army was crossing (wood and stone dam, designed by Gnome Rouge with alot of skill in trapmaking, that was easily toppled by a lever). Another original idea was when a group decided to switch allegiances, since they thought their employers were doomed and wanted to ensure continuing paychecks (never trust mercenaries). My favorite group, warned the people in the way and started forming a large band to harass the enemy and destroy their supplies (the whole party took leadership at lvl 6).
Let the groups form their own destiny. If you tie the social group to the story formed by the RP group, you may find resentment forming or the RP group may not like how the social group is acting.
... AND ON THE EIGHTH DAY, GOD SAID, "I NEED A DRINK."