I think it's pretty hard to judge Nadiya as a pro, as her best celeb was her first year. Some of her choreography for Davood wasn't great, but most pros have a bit of a dodgy first go. Most of the ones who didn't, like Nikita, Kai and Vito had their learning curve another version. Nikita was second out his year on the German one, and I've seen some DS posters say it was his choreography that was the problem (though I've never been able to find clips of her dances, so idk if I agree) and I'd say Vito took until around halfway through the series last year to get it together and ditch the Ballando style choreography. Fleur's Week 1 Cha Cha was a bit of a frantic mess, and her VW was mostly Contemporary.
I think Nadiya deserves another chance with someone good. It's a shame for her (and Luba) that good tall male celebs are hard to come by. It would be very interesting to know how Bobby would have done with her, but I would imagine their personalities wouldn't have gone together very well.
Also, probably an unpopular opinion, but I will die on the hill that Davood's Argentine Tango was better than Joe's, everyone just lost their minds over the unusual lift, and I'm still mad he went out on it instead of Molly or Gemma that week.