So i was looking at nilfgaard in the deckbuilder and something immediately came to mind; NG doesnt have enough super high provision cards, this is why i think NG has only ever played ball because there are no other archetypes supported by their high end provision cards.
Lets compare NG to other factions:
NG has 3 12+ provision cards.
NR has 8 12+ provisions cards.
MO has 8 12+ provision cards.
SY has 5 12+ provision cards.
SK has 6 12+ provision cards.
ST has 8 12+ provision cards.
This i think is the problem; It doesn't allow for a lot of variation, You either go for a ball deck or create some kind of midrange deck which is usually clog or maybe hyperthin nowadays.
I would like to see in the future that NG also gets more high end provision cards to support different archeypes; NG mages, NG Soldiers, NG Agents/Spies or maybe even bring back more support for NG alchemy in a future expansion.