When Ray Blanchard wrote his findings in his book in the late 1980's the world was a very different place and he was taking a snapshot of the society at the time and how transgender people fit into it. This means there were very few female to male transsexuals transitioning and the early and late onset pattern (essentially following the fault lines of androphilic and gynephilic orientation) appeared to be somewhat predictable.
Of course what has actually happened is that the new openness of today has begun to dismantle this simplistic model. Gynephilics are transitioning sooner and female to male transsexuals are far more visible.
What this suggests to me is that we are dealing with a spectrum rather than a rigid model and with AGP now debunked by the new generation of trans researchers and trans people themselves, we are seeing something closer to what Harry Benjamin proposed which itself was far from perfect.
If you permit me the use of archaic definitions for a moment, the old dividing line between transvestite and transsexual is even more blurred than ever showing us that trans people themselves have trouble self diagnosing. I have mentioned here recently that Benjamin would often get the diagnosis wrong and his type III transvestite would suddenly transition. Regardless both those definitions have fallen out of favour and are no longer used by today's generation.
So at the root we are back to the concept of what we call gender dysphoria which we don't really understand. To say otherwise would be being disingenuous.
In this spectrum concept you don't so much have fixed typologies but instead people dealing with their dysphoria differently depending on their circumstances; androphilics more readily transitioning because of the alignment with orientation and gynephilics resisting due to misalignment.
But the debates rage on because people need personal narratives to understand themselves and justify decisions they have made in life and when someone else's threatens yours it stirs the impetus for spirited discussion. The reason we go in circles is that we are missing data.
Is gender dysphoria real? You better believe it is and many who follow this blog have experienced its power.
The difference for me now is that my internal peace keeps me from needing to argue very vehemently any longer. All I need to know is that the evidence we seek is beyond our grasp; at least for the moment.