With the first set of twins you have an unnatural and unhealthy (imo) obsession with staying identical. This was likely a natural enough coping mechanism with trama and stress in life, but will probably cause issues...BIG issues if they don't deal with what caused it, and keep growing their mental attachment to being identicle.
My dad is an identical twin. I am super thankful he is not a carbon copy duplicate of his older brother, but rather lived his own life. My dad broke generational trends of substance and physical abuse, while his brother did not.
With the second set of twins you have two girls that are each unique personalities, but are happy with the differences that they have to work with....and they love each other! Brit and Abbey will someday, if/when they marry, have a closer then sisterwife bond with each other, and their hubby will have two women in one body to get to know. The boyfriend of the other twins will have (or has) two women to keep up with in bed, two women to provide for?? (meals, clothes, health care etc. Do they work?) but not really much variety. Their obsession with sameness may be agreed upon, but what if one, or both start stifling her differences out of fear of hurting the other?
At any rate the guy that gets the two girls that match has their imperfections times two, and the guy that gets the girls that share a body gets two with different strengths and weaknesses. The guy with two whole wonen might have more children, but that would be if the carbon copy women didn't abort pregnancies that didn't happen simultaneously. I'm not saying they would but I have no idea how far they would take their desire for staying identicle.
Both make me thankful for the degree of normalcy I enjoy.