Since no one has jumped on this yet, I'll give a few thoughts. I'll use fellowship block examples to keep it simple.
As far as number of companions, perhaps I'm playing a Last Alliance of Elves and Men style deck. I start
Frodo, Old Bilbo's Heir and the ring,
Isildur's Bane, and then
Legolas, Greenleaf and
Arwen, Daughter of Elrond. This gives me three companions from the start, two of which count towards spotting for Last Alliance.
Now, obviously, I need some gondor companions to put those conditions on. So, I'll likely run 4 copies of
Aragorn, Heir to the White City (4 copies because I'll draw him faster not having to rely on
the Prancing Pony, and I can discard extras to heal him). I'll run 4 copies of
Boromir, Defender of Minas Tirith. Playing this many copies will likely allow me to draw Aragorn and Boromir in the first few reconciliations I take for the game. Then, I'll throw in a copy of
Sam, Son of Hamfast. Just one because I don't always want him, but if he isn't in there, I'll obviously never see him. I don't usually throw in a lot of extra replacement or splash companions in fellowship block (partly because there aren't as many options).
Faramir, SoD is a great splash companion in any format he is available for play in.
Now, since I have my companions ironed out, lets look at what tools they need. Last Alliance, obviously. We have two Gondor companions, but we wanna see our last alliances early and have some back up in case some get discarded, so we'll run 3 copies in our deck. Also, we have two elves to spot in our starting fellowship but we need at least one more to reap maximum benefit from our Last Alliance, so we'll add in some elf allies. Three
Galadriel, Lady of Light, one copy of
Elrond, Lord of Rivendell , one
Rumil, Elven Protector, and one
Saelbeth, Elven Councilor. These allies have some great support abilities. We'll toss in a
Filibert Bolger, Wily Rascal and a
Bounder as well.
Since we are playing all these elves and
Boromir, DoMT, lets throw in some
Horn of Boromir. Two is probably a good number. It is unique and we wouldn't want multiple copies to combine with other unique card copies to clog our hand. We are also only running 3 Boromir, so we don't want to be getting the horn well in advance of getting him.
Aragorn is gonna be a key fighter for us, so lets throw in 2
Ranger's Sword and 2
Flaming Brand (one of which can be passed off to Boromir). We definitely want to get Aragorn geared up quickly. We'll also throw in a singleton
Blade of Gondor for Boromir. Don't want any extra, same as the horn. We'll throw in a copy of
Aragorn's bow to help deliver some archery or targeted wounding along side
Greenleaf.
Because the Balrog and Uruks are a concern in Fellowship block, we'll run two copies of
Armor to limit the number of wounds our Gondor guys will take.
We've shown the Gondor guys a lot of love already, so lets spread our attention to our elves. Lets throw in a copy of
Gwemegil for Arwen and a copy of
Bow of the Galadhrim. We'll put in 2 copies of
Asfaloth for use on either her or Legolas (2 copies because they are discarded at undergrounds so we might want an extra to play post-site5).
What about our Hobbit? Lets throw him a
Sting (or
Frying Pan if you are really afraid of orc-based swarm).
We'll also support Frodo with another condition,
O Elbereth! Gilthoniel! and some events: 4x
Hobbit Stealth (you'd likely save one or more of these for a site 5 confrontation with the Balrog. Cancel these skirmishes!). We'll also include a singleton
Power According to His Stature as a protection against swarming.
Now you may be thinking this deck looks a little large, and maybe it is. However, we're gonna pair it with Moria Swarm which cycles quite well.
We want a big portion of the shadow side to be comprised on minions, as we are looking to repeatedly swarm until the ring bearer is overwhelmed.
Let's run four
Goblin Runner (more twilight never hurts), four
Moria Scout (usually not hard to spot an Elf of some kind), four
Goblin Sneak (reuse your dead goblins!), two
Guard Commander (turn extra twilight into skirmish wins), four
Goblin Scavengers (replay your scimitars for great card advantage), two
goblin scrabbler (kill opposing Last Alliance conditions, etc.), three goblin warriors (bye-bye, thrarin), one
Ulaire Enquea, Lieutenant of Morgul (crowd control), and one
Ulaire Nertea, Messenger of Dol Guldur (play minions from your discard). So, that is a total of 25 minions. Let's move into conditions/possessions, etc from there.
Four
Goblin Scimitar is amazingly good. Card advantage for days. That will cover possessions for us. They will draw us cards and can be replayed with
Goblin Scavengers. They'll also provide more twilight for us in conjunction with the four Goblin Armories we are adding next. These provide the aforementioned twilight as well as offer some protection for your Goblins from things like archery that can take them out of the equation before the skirmish phase ever starts. We want to see these cards early and often, so that's why we max em out.
Now, we'll also include three copies of
Goblin Swarms. Multiple copies will let us draw into this valuable asset early in the game so we can get the most benefit from any of our skirmish wins.
Lets add four Hosts of Thousands, two
They Are Coming, and one
Relics of Moria.
Free Peoples: 43
Starting: 2
Frodo, Old Bilbo's HeirThe One Ring, Isildur's BaneLegolas, GreenleafArwen, Daughter of ElrondCompanions/Allies: 17
4x
Aragorn, HttWC4x
Boromir, DoMTSam, SoH3x
Galadriel, LoLElrond, LoRRumil, EPSaelbeth, ECFilibert Bolger, WRBounderPossessions: 15
2x
Ranger's Sword2x
Flaming Brand2x
ArmorBlade of Gondor2x
Horn of BoromirAragorn's BowGwemegilBow of the Galadhrim2x
AsfalothStingConditions: 4
3x Last Alliance of Elves and Men
O Elbereth! Gilthoniel!Events: 5
Power According to His Stature4x
Hobbit StealthShadow: 43
Minions: 25
4x
Goblin Runner4x
Moria Scout4x
Goblin Sneak2x
Guard Commander4x
Goblin Scavengers2x
Goblin Scrabbler3x
Goblin WarriorUlaire Enquea, LoMUlaire Nertea, MoDGPossessions: 4
4x
Goblin ScimitarConditions: 10
4x
Goblin Armory3x
Goblin Swarms2x
They Are ComingRelics of MoriaEvents: 4
4x
Host of ThousandsSo, this sorta got into a "final deck" as you put it, as opposed to a starting point. However, I tried to sort of give a rationale behind the inclusion of various things and at what quantity.
A few really general "rules":
For a swarm deck, you want at least half of your shadow cards to be minions, if not more.
For beatdown, its okay to have a slightly smaller amount of minion cards in your deck, as the minions you do play should hopefully have a big impact on the board.
Some decks, like Ninja Gollum play a very small number of minions, but this is because the deck has many ways to recur Gollum/Shelob, making the effective minion count higher in some ways.
If there are certain cultures/strategies you would like to build with, feel free to mention them and perhaps I can give more specific input as far as making a "balanced deck."
Hope this helps at least a little bit.