Sorry, but you misunderstand the rule. Look it up. Since the image is cropped, you have to move back. That's the whole point of claiming 800mm equivalent...you can stand farther away.
And since you stand farther away, any angular misalignment increases blur more than it would if you were closer.
The same logic applies when you increase pixel density. You increase the ability to blow up the image, but you reduce the per-pixel sharpness. If you only got acceptable photos (in given conditions) at 1/300, and buy a new camera with twice the pixels (but the same sensor size), and expect to blow up the image to the same dpi, you have to double the shutter speed to 1/600 to get the same discernible IQ.
A tiny sensor with high pixel count demands either better VR or faster shutter speeds. That's plain physics.
If I use the 300mm on FX camera at 1/300, and use PhotoShop to crop the picture out for 2.7x sensor would get. NIKON 1 just doing that same job behind the 300mm lens, because the sensor didn't capture the whole image of the 300mm lens reflecting in the back. I'm not talking about move camera or image quality. I put my 17-55mm 2.8 on my V1, and using 1/60 at 55mm the image wasn't blur at all. I just saying in my experience.