I honestly have no live experience with beaucerons. There is someone on this board that has one, and I think they're one of the ancestral breeds of the catahoula. If you use the search function at the top of the page I do remember them coming up in discussions before and someone might have left their experiences with the breed.
Also, and this is not directed at you but just wanted to mention it because we have a lot of lurkers reading threads on this forum. I really dislike the notion of dominant breeds/vs. non dominant. These breeds aren't so much dominant as they are independent. They are well able to think and make decisions without human input. You have to earn their respect.
Dominant implies that they are trying to use force to overthrow you, which isn't the case. They just want the things they want, and they like to be comfortable. They don't actually like confrontation. Especially among family members. The other implication is that you should use force to submit them, which is also a bad idea. Many LGDs will see that and think it's appropriate to meet force with force, and they're well aware that they are stronger than you.
Basically, the best way to be "in charge" and have their respect is to be the controller of resources and everything good in their lives. With wild and domestic canids, the one in charge is the one that doles out food, has the best bed, etc. You can share the best bed and stuff, but it's done on your terms. They basically need to work to earn everything they get, and you need to be a reasonable leader (like not ask them to sit 70 times in a row, lol) because they like to see a reason for what you're asking them to do.