Could someone please tell me whether or not this game has a 'campaign' (like some of the saga expansions) whereby it is nicer to have other expansions first?

Thank You!

There is a narrative thread linking Sands of Harad to the previous arc (The Grey Havens and the associated Stormchaser Cycle), but you do not need any previous cards (besides the core, of course) to play SoH.

Ok Thank You!

The Dreamchaser also begins where Angmar Awakened ended.