With the card counts listed in the Learn to Play guide (which also corroborates the Spanish box contents reveal) and the tutorial decks posted today we can now determine how many of each card is in each core set.
Short version: Every single clan card in the box will be 1x. Every single neutral conflict card will be 2x. Neutral dynasty cards will be 2-3x each. Neutral province cards and role cards will be 1x each.
Long version:
There are a total of 7 Stronghold cards in the box, and there are 7 distinct Stronghold cards (cards #1 through #7) -- therefore, there is 1 copy of each Stronghold card.
There are a total of 17 Province cards in the box, and there are 17 distinct Province cards (#8 through #24) -- therefore, there is 1 copy of each Province card.
There are a total of 117 Dynasty cards in the box, and there are 105 distinct Dynasty cards (#25 through #129) -- therefore there are 12 duplicate Dynasty cards in the core box. Between the L2P Crane and Lion decks and the suggested decks from today's PDF, we can conclude that there are: 3x Otomo Courtier, 3x Seppun Guardsman, 3x Miya Mystic, 3x Wandering Ronin, 2x Keeper Initiate, 2x Seeker Initiate, 2x Favorable Ground and 2x Imperial Storehouse. This accounts for all 12 dynasty duplicates -- therefore, there is 1 copy of every non-neutral Dynasty card.
There are a total of 98 Conflict cards in the box, and there are 84 distinct Conflict cards (#130 through #213) -- therefore there are 14 duplicate Conflict cards in the core box. In the L2P Crane and Lion decks there are two copies of each neutral Conflict card (#200 - #213), which accounts for all of the Conflict card duplicates -- therefore, there is 1 copy of every non-neutral Conflict card.
There are a total of 5 double-sided Role cards in the box, and there are 5 distinct double-sided Role cards (#214-#218) -- therefore there is 1 copy of each double-sided Role card.
One core set will be enough to build tutorial decks and get a feel for the game.
Two core sets will be enough to build tournament legal decks.
Three core sets will be needed to build optimal decks. Without a third core set, all of your clan cards are at max 2x, and there's no way the decks that win tournaments will be constructable with 2x of clan cards.
