Well, a couple of things about that:Here's one. The Arabs were herders and merchants.. They NEVER bred animals too early …. and historically girls did NOT marry until after the onset of the menses.
Age of Aisha (ra) at time of marriage - Muslim
www.muslim.org/islam/aisha-age.htm
First, you have chosen from an admittedly "apologetic" source -- one that claims to be "presenting Islam as peaceful, tolerant, rational, inspiring." Now that is interesting, since you yourself have argued that it's okay to kill those who renounce the faith. And as we see in Brunei, or some of the other capital punishment hot spots like Saudi Arabia, Pakistan, Afghanistan and others, that does not necessarily appear to be the whole truth and nothing but the truth.
Second, your source was written about 700 years after the events in question.
Third, not all hadith are considered equally reputable or valuable by all Muslims, but there are various ahadith stating that Aisha was either nine or ten at the time of her consummation that come from collections with sahih status, meaning they are regarded as reputable by the majority of Muslims.
I do not believe this to at all settled, and as I have said, the majority of scholars disagree with you, and favour a much younger Aisha.