Definitely agree on that one.
I think even if Dean was around and John died instead of Mary I think the boys would still end up different. For all his faults John always drilled into the boys family first. (even though he tended to forget that little bit) Under Mary's supervision, and without people like Bobby in their lives I could see the boys growing up to be in competition with each other, always at odds to prove themselves to Mary. I mean look at how other Campbells turned out. Christian for example. Mary doesn't care about family.