Honestly, Scenarios are tricky and a little odd at the moment. I feel like NG is 100% carried by Ball, while other Scenarios like SC's ans SK's are much weaker. None of them are outright bad, but I feel like a Scenario should be powerful while not carrying an entire faction.
However, if Ball gets reworked, NG needs buffs to other archetypes.
Anyways, on to my main point: One additional archetype from each faction should get a Scenario to help flesh out or buff their archetype.
Imo, Wild Hunt, NR Cursed, NG Soldiers, SK Pirates or Cultists, SC Dwarves or Treants, and SY Witch Hunters should all get a Scenario
I'm not sure what each should be, but I'm sure it wouldn't be crazy hard to concoct. Plus the idea of a Cultist, Witch Hunter, or Wild Hunt Scenario seems awesome to me.
Obviously I think they should follow similar formulas as the other: Engine on deploy, special card or something miscellaneous that either procs the engine or plus plays for points, then whatever else should follow; either another proc, a finisher, etc.
Side rant: I don't understand how CDPR takes so long to add content to Gwent. There's a million custom cards to draw inspiration from; they could use a test version for things they haven't balanced themselves, or they could just release stuff and balance a month later like they seem to do now.
I know balancing and Game Development aren't trivial, but it just seems like they could be doing a lot more. Or maybe I'm just a little delusional as to how many hours go into content creation, seeing as how I've never developed games myself.
Either way, I just wish they would at least look here and try out some ideas/cards all these amazing Gwenters have came up with.