Probably more a case of how the book presents relative to grade and also how grading can vary over the years.
Especially when the Heritage 3.5 copy was graded back in 2012 while the CC 3.0 copy was graded during the extremely tight GA grading time period of summer of 2016.
Virtually everybody that I have communicated with feels the CC 3.0 copy presented much nicer relative to it's assigned CGC 3.0 grade, with absolutely nobody hinting that it might have been overgraded.
In fact, I am aware of some board members here who were bidding on the CC 3.0 graded copy, but had no interest in bidding on the Heritage 3.5 graded copy. It looks like the final results confirmed that this same sentiment went beyond the boards here.
Looks like bidders and potential buyers are now no longer blindly buying the label, and instead, are looking beyond just the label itself and also astutely buying the book.