Actually, you can consider the flamberge as a weapon with a "raw" innate bleeding. Because it has a E scaling for luck, almost Nothing, even for bleed infusion. And surprisingly, the best luck scalings with the same base bleeding in greatswords are first the claymore blood with a D scaling, then the bastard sword blood, then the drakeblood greatsword blood, and finally the flamberge blood with a E scaling! Conclusion : if you want a bleed greatsword scaling with luck, go for the claymore! Or you can try a classic flamberge with carthus resin, but i think it wouldn't be as good for bleeding.