I get it, but I'm not sure about Snell or Bellinger as being good investments. Snell can easily run a double digit walk rate, and I worry about his ability to keep getting the swing and miss once he ages and his stuff declines. Bellinger had a bounce back year, but isn't far removed from being absolutely unplayable. He struggled against fastballs last year, and a lot of his value comes from his defense. I would hate to end up with Jason Heyward 2.0. I do like Montgomery and think he is pretty safe, and I can see him being a Chris Bassitt type FA.
Of course Ohtani is going to cost a lot, but you know you are getting one of the best hitters in the league. And even if you aren't sure that he'll last as a pitcher for the duration of the deal, I would feel confident in his bat, and think he could possibly play the OF.