LiuBeiwasGreat wrote:Cao Song was always Cao Song. It was Cao Song's father who was a Xiahou.
Actually, this is untrue according to Cao Cao's SGZ bio.
Chen Shou wrote: wrote:Teng’s adopted son Song succeeded him, achieving the high office of Grand Commandant, but there were none able to discover the circumstances of his birth.3 Cao Song begot the Great Ancestor.
The Record of Cao Man, composed by a man of Wu, and Guo Ban's Shi Yu both present the following: Song was a son of the Xiahou clan and was the younger brother of Xiahou Dun’s father. Therefore the Great Ancestor was of the same clan as Dun, as their fathers were brothers.
Song was Teng's adopted son, so that is clearly where the change in family took place.
EDIT: I may have misunderstood you. If you meant that Cao Song was adopted at a young age and thus was "always" a Cao, and by Cao Song's father you mean his biological father, then your statement is (probably) correct. "Probably" because we don't know at what age Song was adopted.
More relevant to the actual topic, I have also noticed the prominent role Xiahou Yuan played. If someone was rebelling or attempting to rebel, Xiahou Yuan was seemingly Cao Cao's first choice to go stomp out the insurrection. Clearly he trusted him a great deal. Xiahou Dun, on the other hand, was reputed to be more educated in the clasics than many other military men and I believe he eventually spent more time in government than on the battlefield. From what I've done so far, he is mentioned sparingly in Cao Cao's bio, in the early days of the turbulence created by Dong Zhuo and later as a confidant of Cao Cao. I think Dun was more of a close friend than Yuan, but Yuan was the more accomplished and trusted military commander.