I think everyone agrees Jabari will win ROY. That's not a reason to take him imo.
If EVERYONE really agrees on that, then yes, we do need to take him and that is an EXCELLENT reason to take him. History shows that the guy that is ready to help NOW is also usually the guy that ends up being the best, or one of the best, players in the draft class. Let's go back and look. I am skipping the past 2 seasons because it is too early to tell who the best players are at this point....
2011 - ROY - Kyrie Irving (Still the best player in the class)
2010 - ROY - Blake Griffin (Drafted in 09 though. Missed a season because injury. IMO still the best player in that 09 draft class, but you could argue Harden or Curry)
2009 - ROY - Tyreke won it (wouldn't have if Griffin played that year.... but there were other players that are now better than Tyreke)
2008 - ROY - D. Rose (still the best player when healthy)
2007 - ROY - Kevin Durant (obviously still the best player)
2006 - ROY - Brandon Roy (when Roy was healthy, the only player that is now better is LaMarcus Aldridge)
2005 - ROY - Chris Paul (still best player)
2004 - ROY - Emeka Okafor (Had a solid career, but Dwight Howard obviously ended up being WAY better in the long run... This is one case where potential easily won out over the "ready" player)
2003 - ROY - LeBron (still best player)
2002 - ROY - Amare (only player arguably better was Yao)
In those 10 drafts, IMO the ROY ended up being the best player in draft class 6 times. Amare is 1 or 2 in his class. Roy is 1 or 2 in his class. The only 2 that didn't end up being a top 2 player from their class was Okafor and Evans.
So if Jabari really is a lock to win the ROY, which pretty much everyone has said, then I am going with history and taking him.
* Sorry if I overlooked somebody obvious. I tried doing this as quick as possible and really only quickly glanced at the top 15-20 picks or so.... Point stands either way.*