Was out last night so didn't hear about this as it happened... WOW!!
Great haul for Chicago. Elite prospects like Russell are almost impossible to acquire. If you can get one it doesn't matter if they play the same position or have a similar profile as the elite prospects you already have -- Russell is of immense value to any team. Throwing in Hammel to do that is a no-brainer. I'm sure the Cubs pounced as soon as Oakland told them Russell was available.
That said, it makes sense for Oakland too. Now they're prohibitive favourites in the AL. And they take two top targets away from their competitors. Look for Oakland to re-trade Samardzija in the offseason at next year's deadline for a good return; what Milwaukee did with Greinke comes to mind. They're not just trading for 50 starts of Samardzija, they're trading for him as a tradeable asset.