Yeah... the Greater "rounded head" thing comes from comparing it to the Lesser. Lessers have a peak making a sharp change in head slope direction. Greaters don't, meaning there's a continuous change in direction around the head, giving them a "rounded" look. Imo I think the bill on the male in the top photo is better for Greater due to how large it appears. I agree the head looks a bit odd with the peaked forehead, but I see no hint of a peak near the back of the head.