We saw in 2015 and 2016 that Ross can be a very solid back-end starter or even #3. I like his stuff, he's past the TJ recovery now, and he's coming into his prime. Obviously you want to see it consitently for more than 3 starts before annointing him, but I feel good about him joining Max, Stras, and Corbin next year.
Fedde is showing some promise. Same as Voth did. I believe Fedde only gets 1 more start then is out of the rotation, and hopefully the Nats stay healthy and it stays that way. I wouldn't hand Fedde or Voth the #5 job next season. Not with Max getting older, Stras getting older and having a history of injuries, and with Ross yet to throw a full season as a starter. You want multiple options to fill in as #4 and #5 guys, because they WILL be needed. I like the Dodgers model of stockinpiling starters and using phantom IL trips to keep them all fresh. Like anybody, if there is an overwhelming offer for Sanchez, take it. But I wouldn't shop him. I'd like him to be in the rotation and Fedde/Voth/etc be the guys who fill in as needed.