I’m not sure they have the courage. They will do the “vouch” (pro-wife) thing, bc that would doesn’t break any bro codes. But they will almost never do anything remotely confrontational until another guy disrespects their partner in a grab-assy way. They tend to avoid confrontation with each other. They size up the other guy, and if there’s any chance the guy can hit him back, or he’s outnumbered, he can get away with agreeing with you. That’s forgiven by other guys - they think “well, he’s gotta live with her, and he prolly likes BJ’s”
I’ve noticed that so many men are Mr Big Talk but suddenly lose the power of speech when reality comes a-knocking.