This deck is intended to be played multiplayer. The heroes synergize to engage as many enemies as possible to allow teammates to manage the quest and staging areas. With two enemies engaged, Amarthiúl is a great card that ties the deck together by providing a resource base for both colors and additional resource generation to help us get out our wall. The main source of offense in the deck are the heroes so her 3 attack also works really nicely in the deck.
Tactics Aragorn can do it all in this deck. Questing, attacking, high health and decent armor, he can do almost anything. His ability to remove some armor from enemies is also an essential part of preventing our enemies from accumulating too quickly and overrunning us. Halbarad is again about versatility. With a 2/2/2/4 stat line, and the ability to help with questing while still offering combat support is another plus. An armor attachment and he can hang with a lot of enemies. His second ability is also a crucial part of what drives the deck, which is keeping lots of engaged enemies, even from the start.
The ally list was created to be as beefy as possible. Since the deck wants to stay engaged with lots of enemies, these defends allow us to tread water with engaged enemies without needing to kill them if the board state dictates it. Standouts are Guardian of Arnor, Defender of Rammas, and Redwater Sentry. This wall of defenders should give the heroes some space to counter attack when necessary, and help with defending when necessary.
Some notable card synergies are Steward of Gondor giving the Gondor trait which makes Gondorian Shield a 1 resource - 2 armor attachment. Fornost Bowman and Guardian of Arnor are both supercharged by scenarios with lots of enemies. And Faramir gives us the ability to chip away at quests on our own if the scenario is less combat oriented.