Almost 3 years ago I suggested the opposite sequence of G3 > G2 > G1 on the basis of the physical evidence. Skip to the end of this post for that comment.
I did as you suggested and read through the OP, your comments and the lively discussion which followed. Please keep in mind that this thread is not about the order of construction of the pyramids. That is an entirely separate discussion. I am proposing that there may be no contemporaniety between the temples and the pyramids.
The temples may have existed pre pyramids and that their purpose was not funerary which calls into question the widely held belief that, a priori, the pyramids were constructed solely for that same reason. Of course, if this were the case it further consolidates the suggestion that the causeways are also pre pyramids and therefore not pavements for the transportation of heavy materials nor processional ways for the funerals of kings, but must have served some other purpose.
The absence of any megalithic construction at G1 surely throws some doubt over the accepted paradigm.