Hi Don,
You are accumulating three variations into one point and also assuming perfect work by the builders of G2.
Here are some particulars:
The diagram scale is 1 cubit = G1 South base / 440
The G2 North Base becomes 411.73 cubits.
Actual off-set 251.0634 cubits
Actual inner circle radius: 328.9104 cubits
The NE corner of G3 is off by 1 cubit and in a direction opposite the deviations of the North base mid-point and the apex.
Actual gap at G2 North base mid-point vs circle: 4 cubits less 1 cubit = 3 cubits.
Actual apex gap: 3.3 cubits less 1 cubit = 2.3 cubits.
Those are reasonable deviations for the time and circumstances.
Consider that the builders did not get the sides of G2 equal either:
Scaled sides:
412.54
411.72
411.27
411.19
Range: 1.35
The builders of G3 seemed to have done better. That is probably why G2 seems to fit better when comparing all three pyramids. The builders of G3 took the postions of G1 and G2 as givens and planned G3 to fit, thus compensating for errors between G1 and G2.
Even if we were only considering G2 as evidence of the "quarter-base" method, the fit is very good. When we add the numerous other examples of the "quarter-base" method explaining the locations and positions of structures, it becomes highly probable that the method is valid.
Note that method indicates that G2 is located and sized using G1 as a "tool" and that G3 is located and sized using G1 and G2 as a "tool". It does not suggest that the three were planned simultaneously. Nor does it exclude the possibility that an as yet unknown method was used and that the "quarter-base" method is merely a manifestation of that unknown method.
C. Wayne Taylor
Richmond, Virginia USA