Remove and discard giblets and necks from hens; trim excess fat. Split hens in half lengthwise. Starting at neck cavity, loosen skin from hens by inserting fingers, gently pushing between skin and meat. Combine mustard, rosemary, salt, pepper, and 3 garlic cloves to form a paste; rub mustard mixture under loosened skin. Place hen halves, meaty sides up, on a broiler pan coated with cooking spray. Chill 30 minutes.
Preheat oven to 425°.
Bake hens at 425° for 30 minutes or until a thermometer registers 165°. Place hens on a platter; keep warm.
Place a zip-top plastic bag inside a 2-cup glass measure. Pour drippings from pan into bag; let stand 10 minutes (fat will rise to the top). Seal bag; snip off 1 bottom corner of bag. Drain drippings into a nonstick skillet, stopping before fat layer reaches opening; discard fat.
Add wine to drippings in pan; bring to a boil over medium-high heat. Cook until reduced to 1/4 cup (about 3 minutes). Stir in broth, juice, honey, and 2 garlic cloves; cook until reduced to 1/4 cup (about 2 minutes). Remove from heat.
Remove skin from hens; discard. Drizzle each hen with 2 teaspoons wine mixture. Serve immediately.