I know this will sound kind of dumb, but if I knew was unable to pursue Cole or Strasburg, I would have gone after Corbin last winter and given myself two chances to land a potential TOR starter (along with Wheeler this year).
But my true fallback would have been signing Rendon (he can technically be backup plan IMO), move Moncada back to 2B, and then use Madrigal in a trade for a controllable starter. Money is a powerful asset if you actually leverage it creatively