Diaco on paper is better, but I don't know if he's more inclined to be interviewing for RU, just to secure an extension from UConn.
Ash is coming from a coaching tree under Meyer that includes guys like Dan Mullen, who has never been a head coach prior to landing at Miss State. Meyer's offense under Tebow was not the same once Mullen left and Florida eventually lost to Bama in the SEC title game.
Hermann went from no experience as an OC to 3M and lifelong security at Houston in less than 12 months. If Ash is half as good as Hermann, RU has a chance to improve it's defense, which Diaco or Ash should be able to do quickly.
RU is a decent defense away from being very good (8-4 type of seasons), they have the running game and improving offensive lineman. QB is a gaping hole, but I would like to think that the best player, not the most connected player to the Head Coach will start. As much as Diaco appears to be like Ash, I still see him as one of the types of coaches that would play politics because he's from here and knows people in NJ.
I'd rather have someone with zero influence of connections in NJ, to avoid catering to people that just don't support RU while claiming they do. Win games first and foremost and Ash appears to me to be more inclined to just focus 100% on football and not the landscape of NJ.