If they feel Morel can play 3rd I would be ok with him there and then trying Mervis at 1st again. Then, like you said either trade for Polanco or someone else that can play 1st or 3rd. Or they can sign Candelario as a fall back at either position or Garver/Hoskins as a fall back at 1st. Also whoever they got could be a DH option as well. That would leave them enough to either sign a higher end pitcher. Maybe not Yamamoto, but maybe Montgomery. Or they can trade PCA for a young controlled pitcher and bring back Bellinger. As you said, they can’t fill all with FA. They have to trust some youth and it needs to come through.
I also think they will go past the first tier in spending this year. They have a decent amount coming off next year with guys they can fill with young talent. Stroman can be filled from within with young talent. They lose Smyly, Mancini, Barnhart, Gomes and maybe Hendricks salary. And none would be hard to replace for less. So if they did go over in 24’ they should be under again in 25’.
Obviously this is just one option. The point is, IMO if they are aggressive this off season and are willing to go over the LT in 24’ there are a lot of ways they can get good enough to add 7-10 wins to their total in 23’. But even being aggressive they will need to depend on some youth as well as some guys they get in trades.