In this case it means NOT personal opinion. Your quotes are nothing but the opinions of your sources. Neither you, or they apparently, provide
concrete verifiable evidence and without THAT their opinions are worthless. Thus their claims are reduced to nothing than examples of the appeal to authority fallacy.
Once again no evidence to back up that claim and it is the same circular argument. You can cite no early primary source for verifiable for this claim. I am sorry but it simply does not exist.
So either you have hard evidence that anyone check to see for themselves in order to verifiable these claims of yours or you don't? As I pointed out above, the opinions of your sources without verifiable evidence is nothing more than the appeal to authority fallacy.
I deal in facts, hard verifiable evidence, not mere opinions. The opinion of others, scholars or not, carry no weight without supporting evidence that can be examined, tested, and consequently verified.
Theories and hypotheses are only as good as the verifiable evidence used to supports them. Without that is it pure speculation at best, nothing more.