Class-first is not class-only. In the history of feminism and antiracism, class-first leftists were at the front: Fourier gave feminism its name, Engels wrote about the oppression of women, the CPUSA defended the Scottsboro Boys, Du Bois was a communist, King and Rustin were socialists...

Here's a favorite quote by an anti-capitalist who you will recognize:

“I believe that there will be ultimately be a clash between the oppressed and those who do the oppressing. I believe that there will be a clash between those who want freedom, justice and equality for everyone and those who want to continue the system of exploitation. I believe that there will be that kind of clash, but I don't think it will be based on the color of the skin...” ― Malcolm X