Id say to put Shumpert in the starting lineup over Fields now, the 2nd unit can look like this Baron at PG, JR at SG, Fields at SF, Jeffries at C or Harrelson and Novak at PF?

1st unit would be automatically better with scoring, and defense and 2nd unit will be good with defense and rebouding, Fields is a ok defender but a good rebounder, Jeffries is a great rebounder and defender, etc
yeah Shumpert needs to start, Fields is not a starter in this league and never will be. Shump is better defender and better scorer and most of all he plays with confidence, Fields looks scared out there especially against good teams.