I think they hoped that Hosmer and Mancini would go on a hot streak before the deadline and flip them for prospects.
Mancini was poor defensively and offensively. He had some defensive lapses that cost the Cubs at least a couple of games.
Which, the point of the person you quoted, is the whole issue. Serious teams don't play ****** veterans for the sole purpose of trying to drum up enough value to get some marginal prospects. This team was always good enough to contend if they'd put their best lineup out regularly. The key was it taking 2 months to figure out that included Tauchman.