Barbara Hershey channeling Madeline Kahn

I haven't seen Hershey in much, just Last Temptation, Swing Kids, and Black Swan, so I don't know how she usually acts in a comedy. But I swear, at certain times in Splitting Heirs, it was like watching Madeline Kahn in a Mel Brooks movie. It's not because the character she was portraying was one Kahn played more than a few times, it was the way Hershey was playing it seemed to exactly replicate Kahn's peculiar style of acting. (Not a criticism, I love Madeline Kahn.)

It's hard to describe the quality I mean, but a specific instance is the scene in the Duchess's bedroom when she's coming on to Idle, and especially right after she's dropped him out the window. Her mannerisms, her mumbling abstractedly, her short, abrupt gestures, and looking around wildly (guiltily, but trying to seem innocent) this all very strongly reminds me of Kahn. And another might be when Tommy returns from France, and the Duchess finds him in the grounds. She does that trick of breathing in sharply, audibly, at the ends of words, or while she's speaking. A particular effect that I only ever heard Madeline Kahn do.

Anyway, did anyone else ever think this, or see the similarities?