I see zero reason to add any such FA starting pitchers. Santana, Berrios, Gibson, Mejia, Slegers, Gonsalves, Romero, Jorge, and even Dereck Rodriguez are options.
Are you implying the Twins don't need to add any starters or that they should forget FAs and trade for a starter? I think it would be foolish to go into next season with Santana-Berrios-Mejia-Gibson(?!)-May/Gonsalves(?) as your starters. I think it would be wise to add [at least] one starter via trade/FA.