For reference, German yield was around 1.5%, 0% and 0.25% on those dates (vs 3%, 1.5% and 3% for the US).
The elephant in the room in this kind of reasoning is Japan.
Japan shows that the narrative of "good country" vs. "bad country" and interest rates beyond the control of the Central Bank have little to do with reality.
I don't have the data, but if Germany's yield followed a similar trend down then up, but remained below the US throughout, then the hypothesis holds.