The percentages for ethnicity are not guessed. For each native-born Russian parent, you would be 50% Russian. 25% for each native-born grandparent. 12.5% for each native-born great-grandparent. So, for example, I am at least 25% ethnically Polish, since both of my maternal great-grandparents were native-born Poles, and I do not have the genealogical information to correctly calculate the paternal percentage.
I was wondering how people calculated that...
I guess that makes me at least 18.75% German and Russian, respectively. Correction: at least 25% German and 37.5% Russian.
Anyway, we're starting to go on a tangent, so let's get back to whether or not trans-ethnicity is bullshit or not.
I believe that these are just hormonal teenagers who feel that nobody understands them and are trying to paint themselves as prisoners of society.