You can't just lump all of them together. Beni is under team control for 3 years after Xander becomes free agent.
2019 Pom, Kimbrel (assuming we pick up his option for 18)
2020 Porcello, Sale and Xander
2021 JBJ, Betts
2022 E Rod
2023 Benintendi
I'm not going to worry about Beni just yet (Jesus we have five years of control after this year)
I would let Porcello go. I might even trade him before 2020. I would sign Pom. My guess is DD will too.
I would sign bothe Sale and E Rod. You must have starting pitching.