I've been thinking a lot about 3B the last few days, and I've been thinking about it in the context of TT's great point about not having a set lineup. and I've been thinking about Jed emphasizing the team's needs as an ability to hit RHP instead of a specific position or two.
My guess is the team is going to run Madrigal out there as the primary 3B, but that they're comfortable with another one of the options getting significant time if things break a certain way. Probably Busch, Jed talked up his versatility and IMO his ability to fake it as a 2B has zero utility for this team. He'd be like, 6th on the depth chart? "Versatility" has pretty much got to allude to his 3B experience.
So what's the plan? It's to acquire Bellinger and another bat. And I do mean bat The primary consideration with this guy is offense. Jed wants someone who can compliment the current set of hitters, and if he plays 1B or 3B or something that's a bonus. I kind of like Justin Turner. Minimal splits, pretty much the platonic ideal of a "professional hitter" which compliments Wisdom/Morel, and he is an emergency option at 3rd. Age is an obvious concern but on a 1 year deal shouldn't be the end of the world.
So what you've got is half of your lineup is set. Happ, Seiya, Swanson, and Hoerner all play every day at the positions you generally expect. The catchers have a timeshare, but it's based on rest and pitchers not offense.
CF, 3B, 1B, and DH though vary wild day by day. Bellinger plays everyday, but where he plays depends on matchups. The other three spots depend on the day. Steele's pitching? We want Madrigal and Bellinger manning the infield corners to max out defense. Opposing pitcher is a sinkerballer? Let's get Wisdom and Morel in there. Etc.
This also lets you fold the kids in as they're ready. Put them into the rotation and break them in with optimal matchups.