I think the problem with NXT is that a lot of the credible faces (Black, Riccochet, Kairi, War Raiders, Ember, Nikki) all got called to the main roster fairly quickly. You were left with a lot of mid-card baby faces to fill that void. The decision to make the Undisputed Era a sort of horseman like stable where they hold all the gold sort of doubled down on that (not that I disagree with the decision mind you... just mentioning the downsides).
But the Undisputed Era and Bazler will be called up to the main roster at some point, and the things will likely swing back in the other direction. You'll suddenly have no credible heels, and they'll have to rebuilt that. Booking for a devopmental can be tough in that regard.