.....The peeps will be wearing either a Santa Hat or an Xmas scarf and goofy sweaters. It is intended to be rustic and whimsical.
Okay, I thought all would be wearing cowboy hats (wide brims). Wearing Santa hats will not cause a shadow on their faces with being lit from above.
Yes, I saw that too with the shadows, I have to be careful with the hair and clothing. Buttons on the shirt were blowing out, so I think I will want them to wear simple shirts. The extra umbrella just came from B&H and I do have time to try it out. I write down in a journal all my distances and settings of the lights and placement of the modifiers so I can bring it back exactly if I have too without too much effort.
If you are shooting small groups of people and you have time, I would also try using the two umbrellas as a test just to see if your lighting will be more even over the group. Position them a foot or two on either side of the camera.