It sounds like you handled it well to me. Nice that Rookie wasnt scared of the great dane as they are larger. When Bama saw one he was very submissive to it.
I thought about this, but I was wondering whether the dog would see it as getting what he wanted, which was to separate me from the other dog. But I guess the idea is that if he doesn't get me either, he's not getting what he wants. I'll keep this in mind.When I feel a dog is guarding me ("that's MY mom!") I'll storm off in a huff and ignore my dog. I want him to see that his actions (guarding) backfired.
Seems to work really well.