I don't agree, I think most teams take risks with their sixth and seventh starters. These usually are not the complete package.
If I could make a good deal for Leake, I'd do it and use Redmond, Corcino, Cingrani, and maybe one new inexpensive veteran as the tandem in line for sixth starter.
But this thread is about CF and I would NOT trade a major player or prospect for a stopgap CFer. I'd trade someone in the Lotzkar category for a one-year CFer. Maybe two such prospects.