I have run a few groups and prefer that since even though it's a lot of work, I know how to prevent/get rid of any awkwardness that may happen btwn new people who don't know each other...so I'll greet every single person who shows up, include them in a group, etc., so no one is left to wander.
Yes, I do that, too, and I enjoy it a lot.

The hosts of my dinner thing (LOVELY people!) did it, too, but there were so many people there...