Yeah. They are realizing how much of a handful she can really be, especially when they saw how nice Medjai was. Once their B was around, he would go over and sit with them and be all nice, but she was growling/snarling at several dogs when they got too close just walking by the owners. They even had to step in a few times.
I find those situations the best for helping teach people about how to be better dog owners, and especially B owners. They're afraid of their own B when I suggested putting her on her side if she gets too aggressive, they joked about losing fingers and said they never have given her a bath in over 2 years because they might loose fingers. Luckily these owners say they come often and are looking forward to trying new things to regain control.
The B did respond a little to me, just tugging on the harness when she got snarly with the lab and didn't show any signs of possibly harming any of the owners or myself, so it's mostly their fear of the snarl than an actual aggression issue, but they should become the alpha or she will completely run the house and it will be chaos as the mastiff grows.
It is nice to see how Medjai reacts to another basenji, especially a female who's the alpha. He growled back a little but never got near fighting and they actually got along after the initial couple snarls. They didn't run together or anything, but that's also due to the fact that theirs wanted to be around to protect the people and probably wasn't nearly as much of a runner as Medjai.