Tess, mainly playing it straight, worked pretty well in my view, she doesn't have the ability to be spontaneous which is needed back stage, and Claudia has that in spades. It may be my imagination, but Claudia appeared to work without any sort of notes. They didn't need Ronnie at all, but despite some very trying circumstances, I reckon (and I'm shocked I'm saying this) Tess did a good job, and Claudia was fab backstage.
Thinking about it, maybe, one of the reasons that Claud worked so well back stage was she spends far more time with the couples then Tess does, she interviews them all one on one each week and builds up a relationship with them, apart from rehursals and the show I doubt Tess spends much, if any, time with them.