Not much on anything Ragnaloardmon or his lines, but I have this really cool Headcannon cause he's my Favorite Digimon.

So, Bryweludramon and Durandamon are absolutely enemies. In every way they're opposites and they fight often enough. Why would they ever DNA Digivolve together?

I think it comes down to their position as weapons, Legend Arms. Eventually, even if they hate eachother. I think they want to be wielded by a worthy Warrior. But being so strong they can't find one. So, when they both grow so restless in that need to be wielded, they DNA Digivolve to make a proper warrior for themselves.

They still wouldn't like eachother, which would explain why they have separate consciousness, but they both do get what they want, the ultimate Warrior to wield them properly.