Slitherine

Hi,

I've been thinking on getting two of the expansions, Storm of Arrows and Sword and Scimitars, and I just noticed that they're also available for purchase at the matrix games website. However, for some reason, the pricing structure and promos are different there and as far as I can tell the two packs come out about 8 euros cheaper (that's a big difference, almost 20%).

I bought the base FoG game here from Slitherine, is it compatible with the expansions sold on the matrix website?

Thanks!