What does this means? (Long way down novel)

Answer:
I believe it means, you can either join someone and work with them and "get down with them" so do things with them, or get beaten by them and be "crushed" by them. Similar to the saying if you can't beat them, join them. Just a bit different meaning pick to join them or get beaten by them.
Explanation:
I'm not 100% sure but this is my best interpretation. I hope this helped!! Brainliest if it did?? No pressure!
Have a great day :D