Longtime real estate broker Cynthia Cowen has joined Dallas-based Hall Group's leasing team overseeing Frisco's Hall Park, which is a 17-building, 2.5-million-square-foot office park in Frisco. Cowen's experience and reputation in the North Texas market will add value to the team, said Kim Butler, director of leasing at Hall Group. "She is well respected in the real estate brokerage community and as we explore plans for expansion, we are delighted to be growing our team with her," said Butler,…