This sign-and-trade will work particularly well if the Knicks end up landing Anthony Davis and if Kyrie Irving signs with a team that is not the Celtics or the Knicks. If Irving does go to a team such as Brooklyn or a wild card team and the Knicks still trade for Davis, this sign-and-trade will be a no brainer.
Getting Davis would be a big piece to this, and if they are able to somehow land Durant, the trade makes even more sense. With two big superstars in New York, a relatively cheap starting point guard would be necessary.