(1) Yes, well I think there's no disagreement that Sweden is far more homogeneous than the US.
Sweden is 99% Caucasian and 66% Lutheran. The US is 63% Caucasian and 23% Catholic. Sweden has 10 million? That's the metropolitan Chicago area.
(2) Here's the way averages work: if US homicide rate is 4.5 (Illinois is 3.5 but let's stick with the national rate) and Chicago is 27, there are five Chicago-equivalents with a homicide rate of 0, or nine Chicago-equivalents with a rate of 2.
Mentioning Chicago as more murderous than Sweden, but failing to mention the nine related cities less murderous is stastical gerrymandering.