D800E with AF-S 300mm f2.8 VRI

The D800E has 36MP and the D3s has 12.1MP.  The D800E has approximately 3x the number of pixels on approximately the same size sensor, 24mm x 36mm.  Now, if I crop 1/3 of an image from the D800E, I would have the same resolution of an image from the D3s.  Am I correct?

For example, if I took an image of an automobile that fills the sensor from the D3s, and compare that image to an image of the same automobile, but it only covers 1/3 of the D800E sensor, and then I cropped that automobile and display 100% cropped, both images will have the same number of pixels?