That would have happened regardless of who was in charge. But I hope we are very selective in trading the prospects. The obvious positional needs are left and third. I don't think we need to make a big splash at either position. But some reinforcement would be smart. I am also skeptical of starting the season with Fried and/or Sims in the rotation. A veteran starting pitching is needed. AA's old team the Dodgers have a bit of a surplus. I'm check with them on McCarthy or Ryu.
I'd be somewhat OK with one rental for the rotation, but given the injury histories of those names I'm not giving up as much for either as they gave up for Garcia (Gant/Ellis/Dykstra). If the Dodgers will take two of Anfernee Seymour, Ricardo Sanchez, Drew Harrington, or Huascar Ynoa for one of them I might bite.
If you've got to spend more prospect capital than that to get someone of that ilk to put in the rotation, bite the bullet and sign Cobb or Lynn (and use the Fried/Sims/Newcomb/Folty types as trade bait) or roll the dice and resign Garcia or bring in Sabathia or Lackey on a one-year deal and keep all the prospects to use as throw-ins in future deals.
I understand not being sold on Sims, and can see the hesitation with Fried (although he's doing all he can to make the worries disappear), but I have no doubt that Soroka and Wright will be solid #3/#4s at the very least, so I'm not really interested in adding vets that will need rotation spots in 2019 unless you're angling for a TOR type like Archer. As it is, you've got Gohara, Julio, Newcomb, Folty, possibly Fried, Soroka, and Wright as 2019 rotation pieces - if you're not adding someone better than them to move them all down a slot, I wouldn't trade any of our Top 20 prospects.