OK you are making it sound like Sox top 5 prospects - Groome, Chavis, Mata, Houck and Travis - are used cars and Dombrowski can spin up their value.
Of those 5, only Travis is close to MLB, and he has to pump up his own statistical portfolio before any one is interested. Outside of his minimum wage price tag, he doesn't look much like anything special in MLB. Every team has a Sam Travis in their system already. Chavis was a guy a tagged to be good trade bait for a variety of reasons. But he's not marketable at all. Groome is the one guy the Sox have who is worthwhile in a deal. His distance from MLB is a huge factor, but he is an upside potential player. Of course, it would help his case a lot if he would actually pitch at some point in his career. 62IP across 2+ seasons isn't going to entice anyone, regardless of what the GM says. Mata and Houck need to get bettrer. Granted, both are still in A-ball, but these two guys have combined to walk 37 hitters in 45 innings!! Like with Travis, players like these two may not be so rare or on anyne's wish list.
The Sox can probably swing deals for a reliever or some average help. In no way can they add any sort of big name quality player. And packaging multiple prospects won't help. When it comes to trading, four quarters do not equal a dollar. Yes, there will always be a stream of players coming up through the ranks. This does not guarantee any of them will ever be among the best 750 players in the world.
Of course, a big part of the reason is that the Sox did unload a lot of farm system parts in a relatively short span, acquiring Kimbrel, Pomeranz and Sale. Hopefully these acquisitions negate the need to add any bigger arms...