Honestly every time I've flown with a group especially if it's a part of a package vacation, it's accepted that we'll be solo all over the aircraft and largely clustered in the middle at the back of the plane. I do NOT see why groups should have priority placement over solo travellers. If groups want to preselect seats then they can do so and if they get bumped then that happens to us who fly solo as well. If they don't the seats they want/need then tough cookies.