Rodolphus knew his brother did find Dolohov's wife to be something of a frustration. "Careful brother, you do not want to obsess about one person, and forget everything else. We know that didn't do the Dark Lord any favours."
Of course, Rodolphus skated very close himself, in his fury towards Snape, but he forced himself to look beyond that at times. Severus would get his day of reckoning, and Rodolphus shivered in the anticipation of showing his displeasure, eagerly awaiting the traitor's last breath.
He laughed, however, at the reaction that it had elicited with the woman. She truly was of no concern, but if she could push Rabastan to greater heights, then all good. "I'm sure that in part that only fuelled this desire for bounties?"
Rodolphus waved away the offer. "I don't think there is a need. Young Montague is doing well enough for now, but I had thought to bring in someone else. Someone new, that we could use."