Not sure how they get along personally, but I think they've found a way to make their 'professional lives' work. They're both basically the men of the house and have to do the men of the house things, so they've probably figured out how to make it work. The key would be to have Bela kind of work independently in several ways so everyone can pretend that he's getting his work done his way and on his own terms and because he wants to, not because someone else is telling him to. 

Sometimes it's hard, you just can't figure out where they fit in, right?

I think I've figured out what Nadya did to get on Elizabeth's bad side. It has to do with how recklessly she fed.