Shouldnt be Leadership about leading allies into battle (or whatever)?
So far in the game Leadership isnt the sphere you'll want to include many allies even though it has more allies than the other spheres in the core set.
The only good one is Faramir (but he is unique though so you can only have one in play)
Brok Ironfist is highly overpriced and has a crap ability
Guard of the Citadel is weak compared to other 2-Resource allies
Son of Anor has an interesting situational ability but weak stats for a 3-Resource ally
Silverlode Archer is ok but not better than other 3-Resource allies
Snowborn Scout is ok for a cheap blocker but still much worse than Henemarth
Longbeard Orcslayer is overpriced too
I value following allies as good/above average (ratio cost/attributes and usability of abilities):
Faramir, Northern Tracker, Wandering Took, Beorn, Veteran Axhand, Horseback Archer, Erebor Hammersmith, Henemarth Riversong, Daughter of the Nimrodel, Gleowine
That gives this distribution of "good" allies:
Leadership: 1
Spirit: 2
Tactics: 3
Lore: 4
I'm puzzled of the fact that Leadership has the worst allies...