The key is to make sure Bieber coming back is the Bassitt replacement and effectively Yesavage is the Scherzer one ( or however you want to frame it)
Getting Bieber at effectively 12M is a tidy piece of business, but you really want to aim for a SP better than him to make this rotation very high end.
I think from a pure stuff standpoint Cease and Framber are the best fits. Cease is simply the best SP on the market flat out, the fact they tried super hard for Burnes makes me think they will look here too, and Framber has just been an absolute rock while he's been in the league, is a lefty and generates a ton of ground balls. The issue with him would be clubhouse fit, he might be the wrong kind of asshole.
The next tier is King, who i think has the stuff of the above two, but has health issues that make him riskier, i would have my medical team all over this. Ranger Suarez is 4th and probably a distant 4th, he has some of the same health concerns as King, but is coming off a career and healthy year. He's good, but there are red flags.
If my Asia guy in house loved Tatsuya Imai, i'd look at him, and the more i think about it Brandon Woodruff probably belongs in the KIng/Ranger conversation as the 5th guy, and maybe Gallen as the 6th, but i'd want my medicals checked out on the former and my nerds making sure the latter isnt cooked
Pass on Bassitt, Imanaga, Max, Verlander, Giolito, Littell and Elfin, some of these guys are pretty good ( Bassitt) and some of them are terrifying ( Imanagna) but i just want to be in the top or at least top adjacent tier.