One 45 inch reflected umbrella, fabric at ten feet.

Shadows sharper and darker yet - still better than a direct light, but fading fast. The light source is becoming small at ten feet, and this hurts softness. But groups do require a greater distance, for the wider width of the light beam to cover them. However closer is always better when it is possible (closer to be a relatively larger light source). Do not place the umbrellas at ten feet for a head and shoulders portrait.

Note that a 40 inch light at 10 feet is the same angular "size" as a 12 inch light at 3 feet, or a 4 inch light at 1 foot (all fill about 19 degrees of view from subject). Large is what makes soft. Close can make large. Both large and close is even better.