[pjc50]

The usual solution is a "General anti-avoidance rule" (GAAR). This doesn't get into the intent of the tax law, only into the intent of the business action. If there would be a simpler, more natural, and otherwise cheaper way to do it, but it's been done a particular way to avoid tax, then it's unlawful.

[ethbro]

This seems kind of like the "What is / isn't gerrymandering?" problem.

I am not an accountant, but couldn't most corporate structures be reimagined by taxing authorities as an idealized "single company"?

Then calculate the difference between taxes that would be owed by that company vs the actual structure?

If there's a statistically significant discrepancy, require the company to provide a rationale. Or pay some penalty.

[Nasrudith]

I wonder how well that would work for intangibles like branding, patents, or copyright - all three are artificial and can essentially be charged for arbitrarily and the company value is what provides their worth.

I suspect it would be easier to have a subsidiary rate rule - they may charge percentage either net or gross but not expenses for any IP including required external salaries but even that probably has loopholes or inviabilities.