>2)European farmers, who cannot use Roundup or a large swath of other pesticides and herbicides, *have greater per-acre productivity.

That depends on what crop you are talking about and the reasons have more nuance than you are implying. In terms of corn, the USA averages almost 50% higher productivity per acre (174 to 120 bushels).

https://farmdocdaily.illinois.edu/2020/11/the-changing-distr...

On the other hand, I have read that Europe has higher productivity per acre for wheat.

On both of these crops, the differences at least partially are due to the climate differences between the two regions.