If the tax code says that the location of your right big toe decides where your entire body pays tax, regardless of where other parts of that body is located (immediately adjacent to the toe or scattered across the world), then yes, where the big toe is, that's where you pay tax.

The analogy is more like that the location of you navel decides where you pay tax, and you discover that if you shift your weight around a little, your navel ends op on the other side of the line.

The problem is that the tax code fundamentally assumes that businesses are reasonably local and contained operations (analogous to a single body) and only deals with sprawling multinationals through monkey patching in an environment where policies appearing to benefit big businesses isn't exactly a big vote-grabber.