Not that your girls are much different from each other, but you always want pairs to compliment each other and better the off spring. two small birds "can" produce good babies, but if you are looking to build size always go larger as better.
Electric poultry net fence would be a great way for you to split up green space for them as pairs. Easy up, easy down, easy to move and adjust.
With the sebastopols we run 1 gander nly in each pen, yard, group. Otherwise they fight and wings get grabbed and well with the curls and long feathers it can be a mess. The dewlaps are one large group (actually two groups Alpha and Beta). they are on pasture and have lots of room to move around each other too.