I want to play this game with my gf. Is there a huge overlap of singleton staples in core set? We will avoid playing same faction obviously but are there some factionless cards that we will both need but we will have only 3 copies (1 per core set)?
We are considering buying 3 core sets to play in tournaments but 6 is out of the question (we will just choose a different game). And we are quite competetive so we will not be happy with casual decks.
I want to play this game with my gf. Is there a huge overlap of singleton staples in core set? We will avoid playing same faction obviously but are there some factionless cards that we will both need but we will have only 3 copies (1 per core set)?
We are considering buying 3 core sets to play in tournaments but 6 is out of the question (we will just choose a different game). And we are quite competetive so we will not be happy with casual decks.
It's perfectly feasible to have 2 (or more) solid, competitive decks built from 3 cores. The key neutral staples are mostly present as doubles in the core (leaving you with 2 playsets from 3 cores for cards like Rattleshirt's Raiders, Milk of the Poppy, Varys, Littlefinger), and the economy cards are even better - 4x each. As long as you avoid playing the same factions, you might occasionally clash over the plot you want to run 2 of, or a small handful of neutrals (Put to the Sword, Tears of Lys). And you can *easily* proxy those. The vast majority of local playgroups will be happy allowing proxies for those as well.
Lastly, the overlap will diminish as you go on to buy chapter packs as they're released - so even those few cards you'll be able to lean less heavily on shortly.
Right now, this early on with such a small card pool, there could conceivably be cards you will both want to have multiple copies of but be unable to have with just 3 core sets. Once chapter packs start releasing and the card pool grows, that may change.
My advice is: stick with 3 cores and make some friends to play with locally. If they are not "competitive" and plan to attend tournaments then ask to borrow their playset, or the 1 or 2 you need depending on the number of cores they buy (though if they don't buy in for 3 cores you will have them at a significant disadvantage in your games with them -- so I recommend finding some people who are willing to invest at least that much -- it shouldn't be difficult).
If that doesn't work, there is a huge community of players here online and if you reach out to them, and ask, I am sure you can find someone who has a playset of the cards you are looking for and would let you use them if they are not planning to in the tournament. It's not as ideal as option 1, but it works in a pinch.
Both ideas require community involvement whether online or locally, and honestly, without that kind of community involvement where you are investing time into playing with people face to face or online, you may find it difficult to do well in larger tournaments.
The bigger the group, the more ground gets covered when it comes to concepts, ideas, and playtesting through them, the better prepared you will be.
Welcome to the game, I hope you find a good group that you and your girlfriend can join (start).
Shikaku