Izze's mom vs Carters mom

Izze was a formula fed baby. She slept with us for maybe a week or two. By 6 weeks she was in her own crib and sleeping through the night. The first few nights we did a little bit of cry it out with her. She handled it fine. She's resilient. Izze didn't get held often (she would fuss, it was a hot summer and she was a hot baby). She preferred to swing or ride in a stroller.
Carter had some formula during her first week of life; but since then has turned to exclusive breastfeeding. Carter sleeps ONLY with her mom. The idea of a crib disgusts her. The idea of her crying it out; makes her mom's heart break. Carter's mom is not as resilient as Izze. Carter is held or worn pretty much 24/7. She has a sling; a k'tan; a Becco and a wrap. Carter prefers to be with mom.
Some of this is the difference in kids. But a lot is the difference in their moms.
Izze's mom was a first time mom just trying to survive.Carters mom was having her final baby and trying to savor every second with her.Izze's mom was okay with sharing Izze and not being "favored".Carter's mom really likes being her favorite and is a bit selfish about it.Izze's mom wanted easy.Carter's mom wants whatever Carter wants.
I don't know if its third child; I don't know if its final child; or if its just "THE BABY" of the family syndrom. I do know that its not because I think these things are "better" then I used to; because I still see no problem with formula feeding; crying it out; and not wearing my child. I say you have to do what you have to do.
So I figure it must JUST be that they have different moms.