It's so frustrating when there isn't consistency between both houses, especially when kids get away with A LOT more at one of the two.

My dsc's bm doesn't enforce any real boundaries either.
Are there any consequences for your dss when he's rude or violent (aside from having to sit and talk with you and dh)? Around here, if someone is not able to keep their hands off another child we separate them and there's a good chance they'll lose screen time for awhile. If someone is grumpy and rude, it usually means they're hungry or tired and we'll make sure they're in bed a little earlier than usual. Persistent rudeness usually means a loss of screen time, too. I'm not sure about your dss, but with us, that kind of thing tends to mean they've been playing video games or watching TV for too long.
Yesterday, for example, we took screen time away from my 8 yo dss because he pushed his 3 yo brother - hard - into a couch. When dh asked why he did that, 8 yo dss said that it was because his brother was blocking the TV and he was trying to watch a show. My oldest dss (he's 12, almost 13) has had behavioural issues for his entire life and has a long history of violent outbursts and rages, and bm tends to think nothing is a big deal until he's already screaming and pushing over bookcases. 8 yo dss seems to have picked up on some of that aggression (as he's most often the child my 12 yo dss beats up on) and we're making sure to intervene the second someone gets hurt in our home.
I'm not sure that there's anything else that can be done. Unfortunately, there's no way to force someone not to be a lazy parent.

I'm sorry that it's causing issues with you and your dh - can I ask what, exactly, you and he are fighting about?