As for now, I see Whitlock as a starter in 2022 more than Houck. I think Houck could be a fine closer or top set-up man, but he could also do very well as a starter, especially if he diversifies his pitches.
Bringing ERod back would be fine with me, but he will likely not improve our rotation over 2021, unless he pitches like 2018-2019 and goes deeper into his starts.
I hate the idea of signing a 5th starter. I always hate that.
I'd like to see us acquire a solid 1/2 slot pitcher, but that is not easy. We can pay large and long for Gausman or Syndergaard, but they do not seem like the type you wait years to go big on.
I think the better idea is to try and get a shorter term deal with an aging stud like Scherzer or even Verlander/Greinke/Kershaw (not all that old).
We also need to fill a big slot or two in the pen, even with Houck taking Whitlock's place.
I like R Iglesias, but he's going to cost a lot. We may end up trading for pen help.