Women can easily marry into other groups while it is much harder for men to defect from their own ethnic/racial group
Uh... no it's not. There are countless examples of men race-mixing. About half of people involved in mixed-race couples are male. You've clearly drunk the "women are unfaithful" kool-aid of the alt-right, which is pure bullshit. There's no "reeeeeee Y chromosome" from any group at all.
And no, Ashkenazis don't oppose race mixing. Jared Kushner? You've pulled that claim out your arse. Jews are the most friendly group to race mixing tbh, so idk why you think you can use that as an example for your flawed idea.
Blacks are one of the most accepting groups in the world.
Why do you break up whites into Germans, French, Brits, Spanish, etc. but you don't make any distinction between Blacks? You say Germans are a small group, but then compare Germans to Blacks. They're incommensurable because one's an ethnicity and one's a race. Your entire ideology is flawed.