You're wishcasting on Hannigan and Dickerson. I think it's more likely that one of them never sees 500 at bats in a major league season than they turn into valuable regulars.
I can accept the starting pitching is an asset, but it does get hurt and it is volatile. Could what they have go through the roof? Sure it could. But it can also crash and burn which means your counting on Ramerez, Livingston or Maloney.
Last years' bullpen was an asset, but it's gone. 3 guys who each gave you 70 good innings (Affeldt,Weathers and Lincoln) will not be back. Essentially, they have to reform the whole bullpen. Bray and Burton have been hurt for sections of the last two seasons and it's entirely likely that Nick Masset matches his lifetime era of 5 instead of the small sample he put up at the end of the year.
I hate to bring up the spectre's of Austin Kearns and Wily Mo Pena, but sometimes young players don't take steps forward. Sometimes they get hurt or regress for other reasons.
There is some talent in the organization, but it's thin and not broad based. There are several pieces of the puzzle that you can squint at and pretend you have a solution, but the whole is not in place yet. At this point shopping for a high priced left fielder makes less sense than getting Cordero did last off season. Will it help you? Sure, but no where near as much as other moves could.