Hi, just like you, my eldest was given more fm than breast milk while my 2nd and 3rd are fully breastfed. For me, it is the other way round. My eldest was gassy, always cranky, whiny. My 2nd and 3rd are very easy children to take care of. They rarely cry and are very cheerful. Even relatives and friends commented on this.
I think it is not the difference between fm and breast milk. It is maybe the child's sucking. The child could be sucking in more air if not latched properly.