This is good leadership deck built for only core cards (i dont use 50 cards in this deck because i think its kind of boring rule)

Heroes: Aragorn and Theodred

Leadership

Allies

1x Brok ironfist

2x Faramir

2x Longbeard orc slayer

2x Silverlode archer

2x Son of arnor

3x Guard of the Citadel

3x Snowbourn scout

Events

1x Grim resolve

2x For Gondor!

2x Valiant sacrifice

2x Sneak attack

Attachments

2x Steward of Gondor

1x Celebrians stone

Others

3x Gandalf

Other cards what i use in this deck are: 3x Durins song and 1x Boots from Erebor

This deck is pretty simple: Get resources with steward of Gondor and buy with that lots of allies, Faramirs ability is good for doing guests, when you have lots of allies your will power can raise over 20 in best cases and for Gondor! will work those tough enemies like Ungoliants spawn.

That was all and i know that its not best deck in the world but i have completed 5/6 guests with that deck (in normal mode) so you can try it