It would be easy to mistake the Universities at Shady Grove as a flagship public school, with its red-brick buildings and its state-of-the-art labs, library and fitness center. But Shady Grove is a program unlike any other, with nine state universities converging at the Rockville, Md., campus, part of an effort that began 16 years ago to reduce college costs, produce an educated workforce and encourage college completion among populations that traditionally struggle to get their ­degrees.