The Dom storyline came from Vince - except it didn't. Dom was a babyface under Vince. Dom turned heel, joined Judgement Day, and became the Prison Dom character entirely during Hunters direction. He "came up" with the entire story.
Bloodline and Sami came from Vince - In the lead-up to Elimination Chamber, Sami stated in interviews that his role was only meant to be temporary and was not meant to crossover with Roman, and that only after Hunter took over was he allowed on camera with Roman. Every classic segment (Sami meeting Roman for the 1st time, Sami receiving the Honorary Uce Shirt, the Ucey promo, the trial of Sami, the beat down of KO and Sami at the Rumble) occurred with H at the helm. He "came up" with all of it and can easily be contrasted against the BloodlineWinz fatigue that was setting in prior to Vince's ouster.
Cody story came from Vince - Debatable at best considering Cody has only just now comeback. Irregardless, Cody's story with Roman kicks off in full on Friday, so the success or lackthereof to follow really cant be attributed to Vince.
To stay on this point; it's a continuous medium. Of course these characters existed before Hunter took the book. But the directions of these characters have obviously been altered under Hunter's watch and the different story arcs that have transpired under his direction are obviously his responsibility. These are different stories than what Vince was telling. He's "coming up" with the stories every single week that they produce television.
If you disagree, then I ask who is responsible? Vince was not involved in Ucey getting over, or Prison Dom, or the ascension of the Judgement Day that was floundering under his watch, or even the Bloodline's resurgence after fans complained that their story had grown stagnant. So who gets credit for that? It's not surreptitious. There was an obvious improvement in show quality when Hunter took over. Hunter "came up" with a more compelling show, filled with more over characters, and told more complete and coherent stories than Vince did. That he did them with the same characters, is a design of the continuous nature of Pro Wrestling, it is not a design flaw.
TLDR: Vince made it a hot line and Hunter made it a hot song.