There are no studies that show that the risks of surgery are less than going into labor with a large baby when mother and baby are otherwise healthy. There are studies that show the risk of surgery is higher than vaginal birth for healthy mothers and babies.
Most posterior babies rotate in labor sometime before their head is born. It is more important whether, when you are a first-time birther, baby’s chin is tucked to their chest. Such a baby has a flexed head. Flexion allows rotation more easily than a chin-up baby. Body work, hula-hooping on the birth ball, walking and belly dancing all help the chin tuck. Work on this in the third trimester of pregnancy so baby’s head is flexed by 38 weeks.
Even if a woman labors and then needs a cesarean, her baby will be blessed with benefits of labor. The cesarean for a head down baby in labor that is not fitting the pelvis is not usually an emergency cesarean because the baby is unlikely to have a sudden emergency in such a scenario when the mother is getting good care. Monitoring will help the doctor/midwife know if labor is hard on the baby. The best strategy for a long labor is good labor nutrition and rest without drugs, a sense of humor and lots of patience. Strong labor and good movement can be tried before assuming the baby won’t fit. Pauses in labor are common while the head molds.