It's hard to say I think.
Wasn't the first hoohah about ringers about Denise Van Outen? Am I remembering that right?
We could, I suppose, say also that - come on, you'd have to be a bit daft once you've signed that SCD contract (how far ahead do they know?) not to have a quick go following some YT lessons etc. I very much doubt ANY of them come to it completely never having even seen a foxtrot etc.
Particularly as every single one of them always swears on their dead relly's grave that SCD has ALWAYS been their favourite show and they've not missed an episode since they were 4.
That said, there are obviously ringers and ringers. Most of them are the products of years of trying to get into showbiz and it's rare that an actor won't have danced, or a dancer won't have sung. Etc.
Too much ringery though irritates the public, as we see year after year.
On the Spoiler public votes, Molly is constantly bottom. Hamza is constantly top and everyone else shuffles up and down gently.