Now that I've gotten a chance to play my Dorans, I'm really liking this deck. Harbingers are really an essential part of this (and with Dorans around, they're 3/3s for one), and using Unstoppable Ash combined with them can re-trigger on entry if anyone manages to kill off your natural 5/5 trampler. Evolution Charm can search for swamps or plains on turn 2 so you have the right colours for a Doran on turn 3. Having two untapped lands, one being a forest, lets everyone know there's always a chance you've got a tower defense waiting.
My goal for the deck was to take cards that would generally not be played (Forbidding Watchtower, Lagonna-Band Trailblazer, Skinshifter, Slagwurm Armor), and make them into an offensive powerhouse while negating things like Dragon Hatchling and Flamespeaker Adept. The idea of equipping a Slagwurm Armor to Tree of Redemption, sac'ing it for 19 wolves to Feed the Pack, then Tower Defense for almost 140 damage is just beyond funny.
Downsides: The deck doesn't like its Doran being removed, nor does it have much in the way of removal. There are plenty of ways to get Dorans from the deck/grave, with 4x Dorans, 4x Harbingers, and 2x Evolution Charms, and a couple ways to give him hexproof, but I imagine against a kill card-heavy deck, he would not do well. He does have 5 toughness for 3, though, which is definitely an upside. The deck is 3 colours, and with only basic lands and guildgate-speed duals, that could potentially be a liability, though I'm not having too much a problem with it so far. I'm looking for ways to add more card draw, because as it is, I really feel it'd help and access to black could certainly be utilized more.
Upsides: This deck is funny, and provided you can get Dorans out, fairly fast for what it is. It is not an aggro deck by any means, but the fact I can have Doran and a Harbinger swing for 18 trample on turn 4 with a Tower Defense is silly. I just liked the idea of high toughness creatures that are generally useless (looking at you, Armored Cancrix and Catacomb Slug) being viable, and Doran mixes things up by making all-out offensive monsters into tiny, overcosted wastes of a card (Minotaur Aggressor just got even worse).
One of my favourites:
1. Forest, Harbinger (tutor for Doran if you don't have one)
2. Plains/Swamp, Primal Rage
3. Remaining of Plains/Swamp, Doran, Harbinger attacks
4. Both attack, Tower Defense