Then, too, the US has an overarching cultural impetus to FORCE TOTAL ASSIMILATION within 2 generations.
Now, back to the question of comparable murder rates by ethnicity, it is possible to build a proxy for European ethnic groups out of American cities or counties with a population background pretty well tied to a single European country or area. Minnesota is a good match for Sweden. The Upper Peninsula of Michigan is a good match for Finland.
If you do that you'll find that Americans of any specific European ethnicity have a lower murder rate than their far more blood thirsty European cousins.
The same for African Americans ~ their murder rate, in the aggregate, is incredibly different than the murder rates in any predominantly black African nation!
Then there's WWI and WWII ~ you add those two events into the statistical mix for the last century the United States shows up as the most peaceful nation on the planet!
‘’The US has a different class of Moslem immigrants ~ with more education. Europeans use Moslems to clean toilets and wash dishes in restaurants. They get the kind of Moslems who consider those to be high paying jobs.’’
Once upon a time hispanic immigrants were better educated and better off than average Americans too... It will go the same way with the mohammedans.
As for integration... Just look to Dearborn...
Your percentage of muslims is lower and thus they are (slightly) more peaceful. As their numbers increase you will get the exact same problems that *every* other country that is victim of the muslim mass-migrations.