I think ... Eteri uses Daniil because he know's how to do a program that benefits the skater ... maybe they don't have the best music cut ... but every eteri's skater owns the program ...
Look at Zhenya ... her SP last season didn't suit her ... but when she was with Eteri ... she own the programs even with voices and mimics
The other SP from Misha suited her well, the OCS may have suited somebody else but for Medvedeva it was completely out of place, a step to a completely wrong direction. That is also proof of my point, choreographer should know skater closely (character, strong and weak points) before making a program for her.