Stephen is absolutely being groomed so I'd say he is at the top of the chain, but the reality is that pretty much every single draft pick is not Jerry or Stephen or any one man, it's the result of group effort of various coaches, scouts, ect that all create a big board together.
There are plenty of videos that show this...
This is kind of similar to fans who view wins and loses as only the QB and are incapable of understanding that the final score is a reflection of everyone on the field. The draft picks are the same, they are a reflection of everyone in the war room that all settle on a big board together and make their cases for the guys they like. It's not just the guy who hands the card in.

















:strip_exif(true):strip_icc(true):no_upscale(true):quality(65)/cloudfront-us-east-1.images.arcpublishing.com/gmg/6R3RQAWDEBAJFDBOP6BWTZZWIU.jpg)
