The political organization of Germany matters little. Whether the tribes were "barbaric" or politically organized, Germany delivered little value over the last 2500 years (culturally, theologically, economically, etc) compared to what the Latin and Greeks delivered.

When they weren't dismantling the established order, they failed to defend Europe against foreign invasions.

And the only contributions they made to Christianity was Luther's Protestant reform, the biggest theological clownery in the history of Christianity.

There were a few exceptions, notably Bismarck, Charlemagne (although he was more "Frankish" than German, his father and grandfather were born in Belgium), and then Meister Eckhart.

But besides that, my thesis is that European instability was mainly caused by people originating from Germany *despite* its relative insignificance compared to the great powers of the time, and it hasn't changed to this day.