[jkaplowitz]

If you're talking about income taxation of individuals and would otherwise be dual resident in Germany and another country with which Germany has a typical set of tax treaty residency tiebreakers, then the top criterion in the list is where you have a permanent home available to you. If you have a permanent home available to you in the other country but not in Germany, you are by treaty a tax non-resident of Germany regardless of days in Germany or center of life.

That does raise the question of what does it mean to have a permanent home available to you. And that's a much harder conversation as applied to the edge cases. But one can certainly construct viable enough scenarios where it would not be a close call even if one spends more than half the year in Germany, and then arrange one's reality to genuinely match the constructed scenario. Explaining to the Finanzamt (tax office) might need a Steuerberater (tax advisor) to argue with them, of course.