Gondor, traps... and scrying
A solid RCO deck with a very fun and balanced mix flavor of Gondor swarm and traps. The Ents use their knowledge of trees to complete the trap theme. What I like is that it works pretty well most of the time, and it's not a slow-pacing implementation deck as one might have been feared. Plus, this deck let Henamarth Riversong shines at his best, as he boosts three combos : timing of Gandalf + Sneak attack, optimization of Beravor + Wingfoot, timing / type of traps.
Strategy
The heroes line-up is versatile with great draws, resources since the very start, a decent defender to face the first moderate attacks, and a questing support that grows exponentially thanks to Visionary Leadership and Faramir. Plus, you start with a pretty low threat level.
Since Gandalf is the only source of threat reduction, you may often trigger his three different abilities during one single game.
Mulligan for Steward of Gondor and good allies, or Gandalf + Sneak Attack. Attach Steward of Gondor and Visionary Leadership to Denethor, Wingfoot to Beravor. Henamarth Riversong will help her to ready up.
Adjustments
If the scenario does not let you time for side-questing, you can swap Gather Information out for Cram which may be sometimes useful early game to ready either Denethor or Beravor (one may also consider attaching Magic Ring to Beravor or Denethor, however I did not need it during the tests). If there is some nasty Condition attachment, go for Athelas.