I’m also size 10 and narrow hips, actually that should read I was size 10, a long time ago. Three boys, 8lbs, 7lbs 8oz and a bruiser at 10lbs, they all felt like sh***ing a watermelon. So you’re possibly right. We’ll have to wait for a size sixteen mum to say how much difference it makes. The fourth was by caesarean, bliss at the time but worse after.
Ah well, we are all different. Baby number one got stuck, should have had a section, but too late. Very traumatic. Affected later births and an eventually a hysterectomy. Not engaging any more and I'm sure you will understand why.
To be fair to all who had a terrible time , I'm not boasting as we have no control over how easy or difficult childbirth is for any woman . I was just lucky ( or am built like a tank inside ! )