Upgrades: Champion of the Parish and lands to support Thatcher Revolt, Legion Loyalist, Boros Charm and/or Goblin Bushwhacker.

Strategies:
Drop creature: Turn one War Falcon is beautiful.
Drop more creature: Battlecry pulls together the extra damage to finish on time.
Finish them: Dropping a creature on turn four won't do much good here. Use Brave the Elements, Apostle's Blessing, and/or Guardians' Pledge for the win.

With BtE in hand there's some room to hold back an attack for the turn four sweep. If there are five creatures swinging and two have battlecry there's probably 20 damage there. Plan A should always be "turn creatures sideways" but if you're getting walled this might save the day.

I think the next upgrade would be going Boros, but only with a fast land base to keep the tempo alive. Sacred Foundry, Arid Mesa, Battlefield Forge, Clifftop Retreat, Rugged Prairie. Then getting some Hastey dudes for turn four.