10 day dl spots
If Yahoo created "10 Day DL" spots in addition to already in place generic "DL" spots then owners couldn't horde players on the DL and only fill those slots with people on the new "10 Day DL" Once said player is off the 10 day dl then they would have to be moved into the active roster prior to an owner looking to make a new transaction similar to how it is set up for the normal DL spots.
Not sure 'horde' is the right definition when there are only 2 DL spots. I think there should be at least 4. Not sure you can claim more players off the waiver list if a player on your DL has been activated by their MLB team.