To relate the view of 50mm vs. 65mm in the context of another format which you are very familar with, simply divide the FL by the short dimension of the frame size! So 50mm is 0.9x of 55mm, which is like 22mm on 135 format and like 80mm on 4x5 format...super wide. 65mm is 1.18x 55mm, which is like 28mm on 135 or 105mm on 4x5...wide

Keep in mind that while your people will be small, the background detail will be tiny if far away!