I agree that young men raped by men would suffer more trauma than young men raped by women.
However, I don't agree that they suffer more trauma than women raped by men.
Rape is the crime, whether heterosexual or homosexual. There should be no distinction in sentencing based on supposed trauma, as that is a subjective judgment.
Then, by logical necessity, you must agree that there is a rational basis for disparate sentencing for homosexual and heterosexual rape. To think otherwise would defy common sense.