In absence of a grand unified theory, tackle obvious concrete instances when they crop up.
If the different "simple" answers (which I am not sure exactly what that means) solve the problem, then I really do not care if there is some equivalence principle there; just pick one as long as it produces the concrete outcome that you want.
There are many simple answers to that question; who gets to decide which simple answer is the one enacted? Countries F, I, and U are likely to disagree on which simple answer is "best", which is why we rely on laws and courts to frame and adjudicate the issue.
So what you really ask is to get rid of the rule of law so you can target the bad guy du jour directly. Just remember that you may be "the bad guy" tomorrow.
How do you tax a German company paying an Irish company to show ads in France?