Not all that different from the Lord of the Rings party/parties, when you think about it........
Party starts out as characters 1-2-3-4, then picks up character 5 before long. A few adventures later they meet characters 6-7-8-9, that party runs for a few adventures then character 9 dies; shortly after that, character 8 dies and characters 3 and 4 get captured. The few that are left split up into two parties: characters 1 and 2 carry on with the original mission (picking up character 10 along the way) while characters 5-6-7 try to rescue the captives; meanwhile bumping into (and picking up, again) the revived version of character 9. And without anyone knowing it yet, captive characters 3 and 4 have freed themselves and started their own adventure, etc., etc.
And that worked out as a pretty good tale, I think.