I’m shocked by your experience with seckle but not doubting or discounting your experience. There are so many factors that are different I would hardly know where to begin describing them. Certainly your area has higher rainfall, less wind, the trees that you grafted to don’t like this climate very well overall. Perhaps given those factors your account makes perfect sense. Comice is not a strong grower here and seckle is stronger as an example. In my location many times as I passed seckle trees my eyebrows were raised by it not growing but it is growing better than comice.
Absolutely agree it’s possible and have alluded to similar concepts that your bringing up