I don't think any teams draft for need, though. No prospect is going to be ready soon enough after you draft them that drafting for need makes any kind of sense. You don't know what your roster will look like in 2 or 3 years. And in the rare instances where you draft a guys who could be ready in a season, it's the generational talents like Harper and Strasburg or the odd situation like Craig Hansen (which didn't work out, obviously), so it's a pick for talent anyway.
Some teams might pick for organizational depth (or lack there of), I guess... but it seems most teams get that you should take the best talent you can.