Often times, those you are referring to as 2nd or 3rd tier players turn into dependable everyday players. Something quite frankly we haven't had in right field in over a decade. And as stated often times high ceiling players don't reach that ceiling. It may be coaching, circumstances, injuries, lack of development or any number of reasons.
I'm not suggesting they don't aspire to acquire those high ceiling guys. However someone like Abreu who has shown mlb success, built a nice reputation amongst Boston fans, wouldn't be someone to be disappointed about in my opinion. Again, so long as he's not the centerpiece....I don't think he will be.