So, I've read Recruitment Drive, In the Gutter, Legacy of Darkness, Night of the Carver, Bad Blood, No Strings Attached (FMed), Landslide, The Great Race and, as I understand they are all intended to be introduction or intermission adventures for Fated with 0-2 Steps. My friend FMed In the Gutter, Night of the Carver and Bad Blood and use them in such a way too - the beginning of your own campaign based on Fated Destiny Steps (an article from WC21 by Mason Crawford helps a lot). As for WC adventures it's the same but as for me they seem mostly intros for 0-Fated rather than intermissions for more experienced Fated. But some of than can give very strong opportunities for the beginning party - as your own train with pet necroengineer from Train of Thoughts (FMed).
Nythera (FMed) is sure mid level adventure with exellent plot hooks and dangerous combat ever for its own pregens.
And I should notice that using skill triggers from Into the Steam and new Pursuits with Zero Step benefit (Into the Steam, Under Quarantine, new Gremlin book) make generated Fated more strong and competent characters than their vanilla counterparts, which is also should be mentioned when you are determine "difficulty level" for them.