Having multiple small propellers along the wing is done for lift augmentation. See the X-57 concept plane for an example. If this is anything like the X-57, mos

Having multiple small propellers along the wing is done for lift augmentation. See the X-57 concept plane for an example. If this is anything like the X-57, most of those propellers will feather upon takeoff. Basically, most planes use wings that are much larger and less efficient than they need for cruising, because they need the extra lift for takeoff and landing. By introducing lift augmentation propellers which can augment lift for takeoff/landing, they can use a much smaller wing which has less parasitic drag and results in more efficient flight. https://en.wikipedia.org/wiki/NASA_X-57_Maxwell https://en.wikipedia.org/wiki/NASA_X-57_Maxwell