European manufacturing is more productive than US manufacturing. The US productivity advantage comes almost entirely from the US' strong tech (as in software) sector.
Tech (as in software) is what's being cut off to Ukraine, and tech (as in software, MEMS gyros, and GNSS) is how Ukraine keeps blowing up US$3M T-90 tanks with three or four US$500 FPV drones. So I think it's highly relevant to the question of sovereignty.
As far as I know all cheap drone tech is provided by China (to both Russia and Ukraine).
It's largely kind of an international open-source effort, but there is a lot of crucial hardware that is only available from China, yes. Until this week I think Anduril was in a good position to become an alternative to China in two to four years, but this move strongly undermines their credibility overseas.
(Might be just me but it took a couple reads to understand you don't mean US tanks that cost thee million dollars. For me, USD is the currency code I'm familiar with)
Apologies. Around here people commonly write "U$S" but I'm not resigned to that yet.