Ideally I think they should just combined Greenskins and Gitmobs together ( with the Giants and troll ), give them their own battletome, update a few models and make them like the Imperial guards of destruction, Where they have really loose battalion keywords that allows them to ally in with every other Destruction factions without taking up ally points (like the chaos battalion do in BoC) but still be able to play as themselves.
IMO I still think that Spiderfang, Moonclan, and Gutbuster with Maneater (Firebellies?) should get their own Battletome evetually