Perhaps the numbers are being confused between the personal income tax rate (so where inbetween 15-22 % across the EU) and the combined deduction the government takes off the earnings (38-55%).
For a full employment contract, my research the actual values vary very little one country against another. The difference comes from the tax bracket dependent on the income size, family configuration and other deductibles. I. e. A single captain with no kids nor mortgage earning 11k E would see 45 % not reach his account no matter the passport flag. On a theoretical full contract with no ehm optimization.