First pick: Arwen, Lady Undomiel
For the moment, ignore the fact that you will never have two homesite 3 elf allies and the Gandalf signet is useless. Arwen is a warm body, nothing more. Arwen stops Frodo from being overwhelmed by skirmishing with an additional minion that Frodo would otherwise have to face. She essentially provides the effect of three stealth cards in one convenient package. Arwen can lose two skirmishes and then die in her third skirmish, meaning she accounts for three oncoming minions. When one card in your deck handles three cards in your opponent's deck, you're in good shape.

Realistically, I would take a companion over almost any other card in the pack. Even Lorien Elf, which only has 2 Vitality and requires spotting an elf, is twice as good as Hobbit Stealth. But the fact that Arwen is a 3 Vitality companion with a mid-range strength makes her an amazing selection. Almost every companion is a first pick in draft, and Arwen is no exception.
 

Second Pick: Ulaire Otsea, Ringwraith in Twilight
I'm pretty torn whether Otsea or the Warrior should be the second pick, but I sided with Otsea for a couple of reasons. Of course, Otsea is far superior in every starter deck choice except the Aragorn starter. There is a huge difference between 7 and 9 power minions – Frodo without a Hobbit Sword can skirmish 7 power minions but not 9 power minions. So the only reason to possibly play the Warrior is if you think his spot 3 wounds and exert text is a likely situation to occur in game. Having Frodo be exhausted will almost never happen unless your deck is stocked full of Damage +1 minions – hence the vast superiority of Otsea in non-Uruk decks.

But even with a bunch of Uruk-hai, it's unlikely that Frodo will become exhausted. Most of the minions in the Uruk-hai deck have 8+ power. Only two minions (the two Uruk Soldiers) cannot be boosted up to 8 strength using Bred for Battle. So if Frodo doesn't have a sword, he's probably staying out of combat anyway, so he won't be exhausted. Once Frodo gets a sword, he wins skirmishes versus the three Uruk Savages in your deck. And if your opponent knows the Isengard Warrior is coming, he or she can play around it by taking burdens instead of wounds. All of this adds up to a useful but inconsistant ability. Your deck is just better off with a 9 power homesite 3 minion.
 

Third Pick: Isengard Warrior
So even if this guy is just a vanilla 7/3 homesite 4 minion, he's still an attacker, so he'll make the deck. The more minions in your deck, the better your chances of overwhelming Frodo. And who knows – maybe you'll get lucky and exert the opposing fellowship once.

Last Pick: Might of Numenor
This is not a bad draft card by any stretch of the imagination. On average you will heal 2 wounds. This generally turns into extra exertions with Boromir. The problem is that the card is inconsistant and you need wounded companions for it to work in the first place. So often the card will rot in your hand until it's appropriate to play it, and you could still hit a 0 or 1. Don't get me wrong – the card is far better than some of the chaff in the starter deck, and it could easily let your companions deal with an extra 2-3 minions. If you draft it, it will automatically go into your deck. But the other card choices (Arwen and the two Minions) are far more consistent and powerful.

Don't take this card early in a draft because it should come to you towards the middle or even later. Remember, it's the only card of the four choices which has a play requirement excluding it from most decks (spot a Gondor companion). Might of Numenor will get picked later than its power level reflects for this reason. You're better off taking power cards that go in every deck – companions and minions.