According to the rabbanut 80 % of the Russians are not Jews.
As for the Ethiopians there are those & that is the majority that they need giyur,Rav Ovadiah Yosef,ZT"L said they do not need giyur but he is in the minority.
Still the Ethiopians are good people unlike those Russians who are posing as Jews.
The real Russsian Jews are the salt of the earth but the posers are our Mariel boatlift.
You have a source for this (the percentage of Russians Gentiles)?
According to my knowledge, out of a million that came from the Soviet Union about 30 to 50 percent (300-500000) are non-Jews (some have a Jewish father).
About the Ethiopians - the only "Ethiopians" that according to Rabbi Ovadia Yosef ZT"L need giyur are the Falashmura.
The Falashmura are converted Jews. Descendants of Jews who converted to Christianity generations ago, and never having assimilated and therefore, according to jewish law, are fully Jewish, but their children should learn in religous school in Israel.
Another thing about the "Ethiopians" - I grew up with many of them and many of them attended the same school with me.
I can testify that those Jews were proud of their Judaism more than any "Tzabar" (Jews born in Israel) i knew.
Unfortunately the process of secularization is not skipped them and the generation born in Israel actually forgot what happened to his ancestors in exile.
Ethiopian Jews which made Aliyah are well aware of what the Africans (Christian and Muslim) did to their ancestors in Ethiopia.
Those Jews are the biggest supporters of throwing those Africans out of Israel, but there is a new generation. One which doesnt know whay those Africans are the enemy. Some of them even protesting against throwing them out.