Mostly they don't. Sometimes they do. I'm working on an example right now where I didn't even shift the camera at all. But the two version will not doubt be cropped differently when enlarged, and the contrast handled differently. Perhaps 2% of my work involves approximately the same shot in both color and black and white. I say approximately, because there is usually some amount of recomposition even in that 2% category, especially if I'm re-viewing the same subject through the eyes of black and white contrast filter.
But in my previous post, I wasn't even implying replicating results of the same subject. I'm mainly an opportunist, so if I encounter something tempting to shoot in color, that's what I do, or likewise in black and white, if it's potentially worthy of a print. All I was stating is that some people can master both media if they want to; these aren't necessarily mutually exclusive. I even like to display color and black and white prints together. They play off each other.