I just wondered if the small pack expansions in each cycle are related to one larger box deluxe expansion (like LotR or AH), or if they have no connection?

There's no particular connection in this game like you see in LOTR.

EDIT: I think some of them may have cards that work well together (you'd have to check cardgamedb), but there's no strong reason why you need to buy certain packs with certain boxes in this game.