Big fan of Warren, and I think even if the Cubbies don't realize it yet, he's a very viable if not quality option for the 4th starter role in that rotation but I love the Castro move. Classic Cashman buy low.
Not as big of a fan of the Wilson move considering he was effective, controllable and left handed. But apparently the two arms coming back are pretty live and we have absolutely no pitching depth in the system in terms of starters. I think Girardi was also really impressed with Lindgren last year and we know he loves Schreve, so he probably figures he has two lefties. Pazos and Mitchell I'm assuming are also going to compete for roles in the pen.
Cash's work isn't done. Still need another starter imho. Right now rotation looks like Tanaka, Severino, Pineda, Eovaldi and Nova. Lots of injury concerns.
I do hope the Wilson deal puts to bed any rumors about moving Andrew Miller, unless the Nationals feel like parting with Giolito ;D