I went for DanSh0wSt0pper’s method on campaign 2 quest 4. I’ll add the following to optimize the run to give me 150 – 170 orc kills and about 550 – 625 damage per match for the Executioner achievement:
Heroes: Aragorn, Arwen and Legolas
2 x Gaining Strength
2 x Lock Shields
1 x Warrior Sword
1 x A good Deed (need to unlock this card by killing enemies with Legolas’ upkeep ability 25 times)
2 x Elven Blade
1 x Guard of the Citadel
2 x Self-preservation
1 x Traffic from Dale
2 x Westfold Outrider
2 x Favor of the Valar
2 x Imladris Caregiver
2 x Imladris Minstrel (BEST CARD OF THE GAME!!!1!1!)
2 x Beorn
2 x Get the Orcs
2 x Erkenbrand
2 x Spear Wall
2 x Gandalf
The idea is to get to the third part of the quest with “Beorn”, “Erkenbrand”, one “Imladris Minstrel” and a 7th ally in play. Every round, Sauron’s side will be filled with “Dol Guldur Goblins” (actually an Orc) giving the opportunity to kill 7 orcs per turn, given that the optional objectives are cleared as soon as possible.
I’m almost certain that an orc dying by attacking one of your guarding characters doesn’t count for the achievement. For this reason, your guard characters shouldn’t have more than 2 attack (fully healed Beorn, Arwen, unarmed Aragorn, unarmed Legolas, Erkenbrand or Guard of the Citadel) so every time you repel the attacking enemy with a guarding one, it will survive for you to kill it later. As the optional objectives will grant +1/+1 to a random ally or hero there will be situations where a usually 2 attack character, for example a fully healed Beorn, cannot be used for guarding given that by guarding with a +1/+1 bonus it will outright kill the attacking orc and thus not count.
Also, related to the Executioner achievement, damage dealt to an attacking enemy by a defending guarding character also doesn’t seem to count based on my calculations and the achievement tracker progress.
Use the two Gandalf cards to extend the match by selecting the “remove 3 threat” option when he enters play. You can also include the “Favor of the Valar” preparation cards to extend it even more; save the "Gaining Strength" events to be played before the Favor of the Valar in case Sauron has the “Dark Sorcery” treachery in play, which is essentially a counterspell. Also, the 2 willpower cost fate event in this section will also help reduce 3 threat while also damaging all enemies (if combined with a “Get the Orcs” card can kill all the orcs and give a respite turn if needed).
I have two copies of Beorn and Erkenbrand (both unique allies thus one copy at a time can be played) in case I need to replace them due to an accidental death, a discard from a Sauron play, or when I need to play Gandalf with a full board; I remove for example Beorn, remove the 3 Threat, and the next turn after Gandalf flees, replace the free space with the other copy of Beorn.
Give the “Warrior Sword” to Aragorn to set him to 3 attack, and both “A Good Deed” and “Elven Blade” to Legolas to set him to 4 attack. The second “Elven Blade” can either go to Arwen to get her to 2 attack or to the “Imladris Minstrel” in order to give her a little more survivability and 1 attack that can contribute to killing a near-death enemy. Also, it’s important to give that extra health because she becomes target number one from Sauron.
In the topic of Sauron trying to kill the “Imladris Minstrel”, he will eventually play the “Elite Dol Guldur Orc” which have surge and 3 attack (there is only one in his deck), usually when there is no guarding character defending and will kill the non buffed Imladris Minstrel. Keep the second copy at hand to replace her if necessary because this card is mandatory to get to the end of the match.
If the match goes without major mishaps, playing both Gandalfs, playing and triggering both Favors of the Valar, using the 2 willpower fate event and destroying any “Watchful Eyes” Hazard Played by Sauron, you can play for about 36 turns (including the turns wasted in the first two sections of the quest) before failing by reaching 50 threat. This will grant a final kill count of about 150 to 170 orc kills per run and about 550 to 625 damage, plus contributing to several other cumulative achievements.