Ok whatever my point is if the point of this is to replicate Marvel you start at the beginning and build from there. The Green Latern franchise will be very limited and have fewer places to explore if you start with John Stewart and give him a contrived origin so he isn't dependednt on Hal. That will all be resolved if you just start from the start. Using the DCAU is a poor example because they had no intention of making the Green Lantern of that show part of anything bigger and he was mainly cast because Hal was dead for several years and they saw it as an opportunity to make the cast diverse without contiuity contraints bogging them down. That scenario doesn't exist here.
They are franchise building, they want a Green Lantern series, Hal is alive, the company is strongly promoting Hal as their main Green Lantern both in movies and on cartoons, etc.