I think you've been way too invested in trying to program your younger brother's thinking. You really need to let go. Your concern should focus on not tolerating abusive behavior from your brother toward you. I fail to see where that's been a problem. I'm inclined to agree with your older brother that your younger brother's views aren't all "that bad."

Trying to control another person's thinking is probably a waste of time. You and your sisters have a right to not be treared in a violent or intimidating manner by your brother. Focus on behavior, rather than on thinking. What he thinks is his business. You seem to be taking great offense that your brother is not a feminist. He doesn't have to be. You have no right to require that of him. Stand up for your rights and don't tolerate him infinging on them. That will have greater impact than you preaching to him about "equality."

I actually think it's kind of admirable of your 6'5", 230# brother to not want to wrestle girls.