Preheat oven to 450 degrees F (230 degrees C).
Rub hens with 1 tablespoon of the olive oil. Lightly season chicken/hens with salt and pepper. Place 1 lemon wedge and 1 sprig rosemary in cavity of chicken/hen. Arrange in a large, heavy roasting pan, and arrange garlic cloves around hens. Roast in preheated oven for 25 minutes.
Reduce oven temperature to 350 degrees F (175 degrees C). In a mixing bowl, whisk together wine, chicken broth, and remaining 2 tablespoons of oil; pour over chicken/hens. Continue roasting about 25 minutes longer, or until chicken/hens are golden brown and juices run clear. Baste with pan juices every 10 minutes.
Transfer chicken/hens to a platter, pouring any cavity juices into the roasting pan. Tent hens with aluminum foil to keep warm. Transfer pan juices and garlic cloves to a medium saucepan and boil until liquids reduce to a sauce consistency, about 6 minutes. Spoon sauce and garlic around chicken/hens. Garnish with rosemary sprigs, and serve.