I mean. Saying Gubanova has better skating skills than Trusova or Shcherbakova is fine, she probably has the best skating skills out of all the Russian senior ladies currently. She also tends to include great feats of skating in her programs.
Nugumanova on the other hand is a slow, empty skater with next to no difficult steps outside of step sequences, no entries and a severe lack of 1-foot skating, and the step sequence's not great either. Of course it's easy to have good flow if you have nothing but crossovers for 90% of the duration. I think Shcherbakova this season has shown much stronger skating skills than Nugumanova, she's actually fixed some of her bigger issues, and at least she's not slow. I don't get how you can look at Nugumanova's step sequence and see her skating as more effortless, for example.
So just using both of these skaters as examples makes it seem, not very coherent, right?
Sinitsyna's of course are good. Snow Leopards in general tend to have good skating skills, as was with Tarakanova, even Kanysheva. And Maria Sotskova to an extent, though I don't remember the exact level that well.
You say that you know Trusova and Shcherbakova have bad skating skills because people "who know what they're talking about" say they do. Well, it even is a bit of a meme how bad skating skills they have, I'd say, that people just keep parroting. Since they really aren't that bad. They're not top of the line by any means, but according to my understanding of the word "average", they still are well above average. Some of these comparisons are just downright insulting, such as Nugumanova.
And Snow Leopards don't represent "average" skating skills. It's the top Russian group in skating skills. And the average Russian skater is quite a bit better than most other countries, perhaps only Japan is up there.