My fully compatible physical decks
Those are my four decks that I keep in my core set box together with a print-on-demand scenario.
I've created them so that no unique cards clash with each other (well, maybe except for Gandalf, but he's a temporary ally). I could make each of those decks stronger on their own, but I wanted to make sure that there were enough copies of any card to make a physical deck (I own three core sets) and so I had to make some compromises here and there ;). This way I can mix & match those decks however I like and just give one to anyone that wants to play the game with me ;). I've tested each of those decks separately and each of them works as a pure solo deck (of course they won't beat every scenario, but they are pretty well-rounded).
The sideboards are rather extensive, but this is just to give players options. Of course tweak those decks to your liking if you want to use them.