Hi Laura,
Great to hear from you again, and thanks for all your help regarding the Pennies & Philps.
Yes, I think you are spot on. History is generally written by the winners and original sources get sparser and more controversial the further we go back.
I've recently noticed some pre-1500 profiles that are causing some controversy because they are poorly sourced or not sourced at all. I haven't yet tried for pre-1500 certification, but imagine that a potential pre-BC certification might be very difficult to obtain.
So perhaps we are better sticking to the AD period.