Rooker really impressed me as well. The problem is he can't really play anywhere defensively and I don't see him replacing Cruz's production in the DH spot. Cruz was the best hitter in the lineup the last two years. With CWS improving in 2021, not sure Twins win the division without Cruz and Rosario. Maybe if Rooker or AK win ROY and give the Twins Aaron Judge-like production, but that's asking a lot.
Rooker does not have to replicate Cruz's production. They need Rooker + whatever player(s) the acquire with the salary the would have used on Cruz to be greater than what Cruz produces in 2021. They definitely need to resign Cruz If the sum of Rooker and whoever they get with the Cruz money is not a net gain.
I am not worried about replacing Rosario's production from the last couple years. He just has not been that impactful and he does not make a defensive contribution. His replacement very well might not be a given a player. It might a RH free agent + Cave and Kirilloff and/or Larnach as the season gets going.
IMO, the relative success where offense is concerned will be most influenced by what happens with all the guys who had a down year in 2020 (Donaldson/Sano/Garver/Kepler/Polanco). If 3or 4 of those guys bounce back a combination of a good utility player / Rooker / Kirilloff and Larnach should be a very good hitting team. Ya know Buck looked gook last year before he was hurt too.