I think that there a lot more brewing behind the scenes than we know of. Part of it is some kind of collaboration with Dish. It's not that Dan is not a visionary. It is that Legere is perceived as a more aggressive competitor and a more aggressive doer. In order to sell this merger to the feds Son will have to show that he will compete with the other two.
Let me repeat myself. In order to sell this merger, Sprint/Softbank should be willing to divest spectrum to Dish (a spectrum swap of EBS for 2000-2020MHz+PCS-H will also be palatable), hosting of Dish's spectrum, promise of aggressive deployment of rural deployment of SMR/700MHz, promise of deployment of fixed broadband on EBS by Dish/Sprint and a perceived competitive CEO will go a long way to sell this merger.