Deck Design Notes:

Path to Exile vs Lightning Bolt?

For this deck I decided to go with speed by cheating the creature drop consistency with Aether Vial, Harabaz Druid, and Collected Company. Path to Exile accelerates your opponent, and it doesn't have the added benefit to finish them off with 3 direct damage. I decided to keep removal to only the playset of Lightning Bolt with more on the Sideboard (work in progress).

Aether Vial Necessary?

Yes and no, this could be swapped with something like Expedition Envoy, but in this particular deck Aether Vial can combo with Ally Encampment to replay the same ally in 1 turn. With Aether Vial in the deck I added additional 2 drops to have more targets.

Expedition Envoy, Reckless Bushwhacker, Beastcaller Savant, Lantern Scout, or Gideon, Ally of Zendikar?

• Expedition Envoy is nice to have as a 1 drop, that can also be played along side other allies to re-trigger their abilities. But as a 1 drop you really want Hada Freeblade, so I decided to put in 4 Aether Vials instead. So Ideal turn 1 drop is Hada Freeblade or Aether Vial. Vanilla creatures are hard choices when selecting what to cut.
• I've never had much luck with Reckless Bushwhacker. It's a weaker version of Akoum Battlesinger, with a trigger that not always hits. I wanted to keep this deck lean, with as few dead draws as possible, and with Reckless Bushwhacker you run into the risk of playing it with no surge cost. Additionally since I am running Aether Vial, it misses the 2 mana cost I want my creatures to have.
• Beastcaller Savant is one of those cards that sound good on paper, then its just meh in gameplay. It speeds up your turn 3 to a 4 drop creature which in a naya deck I'm not really interested in running (for those running black allies though I'd recommend Bala Ged Thief). For 4 mana I want to either drop a Collected Company or possibly a Gideon, Ally of Zendikar, which Beastcaller Savant doesn't let you do. Aether Vial basically does it better, and Harabaz Druid is the best mana source you'll get with allies.
• I actually prefer Lantern Scout to something like Ondu Cleric, specially when combined with Kabira Evangel. But I wanted more targets for Aether Vial at 2, and if I had a choice for a 3 drop it would most likely be a Kabira Evangel to attack through.
• Where the planeswalkers at? I like Gideon, Ally of Zendikar, consistant Ally triggers (check), 5/5 Ally beater for 4 (check), emblem turn of (check, and check). But sadly Collected Company is a little faster by doing 2 ally triggers rather than the steady 1. I would considered sideboarding in Gideon, Ally of Zendikar round 2, expecting my opponent to sideboard in removal, which Gideon, Ally of Zendikar is more equipped to handle.

Land Selection

With 4 Cavern of Souls and 4 Ally Encampment it becomes difficult to have mana open for Lightning Bolts and Collected Company. Fetch lands are crucial for mana fixing in this situation. With the low mana cost, Aether Vial, and Harabaz Druid, sacrificial utility lands are easy to use without losing your mana source.

Personal History

I started playing back in 7th/8th edition. I was young so my deck consisted of Rhox and any other foil or rare card I had. I ended up dropping out of Magic the Gathering, since most of my friends were playing Yu-Gi-Oh! at the time. It wasn't until end of high school that I got back into magic. At this point Lorwyn block had wrapped up and Zendikar dropped. This was a good time to jump back in for me. The meta was healthy, and a lot of the cards both for Standard and Legacy were affordable, and planeswalkers were brand new for everyone. I understood tribal synergy from my Yu-Gi-Oh! decks, but I hadn't really experience it in Magic the Gathering, since I only played back in 7th/8th. I remember going through the starter decks in the store, and a guy coming up to me and telling me to try allies since they were fun. I picked up the deck with Turntimber Ranger in the cover... and loved it. I really enjoy tribal decks, specially interesting ones like allies. I love the toolbox feel you get, that all depends on you playing more allies. Eventually with more allies, you snowball into victory!
I prefer allies in a casual format since you get to use the higher cost ones that really break allies, specially in multiplayer where you get to build up.