Joe, If two people are born from a mother with two uteruses, and they both lived to have children of their own, then to arbitrarily deny one of them their heritage because you refuse to believe it goes against fair genealogy practices.
I am saying that the possibility for multiple births less than 9 months apart is proven to be real. I am saying that it must have happened before. I am saying that if there is strong evidence that two people came months apart from the same mother, then we must accept the possibility that the mother had two uteruses, rather than to arbitrarily deny one of those children their heritage.
I am also saying that this situation is rare, and that we should first look for other explanations, which are much more likely. Just don't throw the baby out with your disbelief. Keep an open mind.