I got the Overrun in Garruk.
There are several reasons I dont use Coat of Arms:
1: When I make "for fun" creature decks, I strive to have no artifacts, enchantments, instants and sorceries, because I go for... A
creature deck. For the same reason I have left out Æther Vial and counterspells in my Sliver deck.
2: I wanted as many cards in the deck as possible to be ELFS. No doubt Coat of Arms would fit in this deck, but.. Coat of Arms has one probolem: It aint an Elf

The only non-Elf cards in this deck are the Planeswalkers. But I like playing with the Planeswalkers, cause it adds an aspect to the game, making it more various and fun to play. And since Nissa searches for Elfs, and her Life-giving ability also depends on Elfs, she is a perfect Planeswalker for an Elf deck. Garruk I' ve added for 2 reasons: First, the Overrun that you ask for, and second because I just like playing with Garruk. He is a cool planeswalker. Its a shame he aint making 3/3 Elves instead of beasts though. However the Beasts are still able to boost Drove of Elves.
You might be right about Ambush Commander, but I just like the fact he turns even the forests into Elves. This somehow "completes" the Elf theme, being able to have absolutely ALL permanents on the battlefield being Elves, cept the Planeswalkers. Also, once the Forests are Elfs, they boost/ gets boosted by both Joraga, Imperious, Jagged, Archdruid, Nissa Revane and Drove of Elves.
I dont know what Timmy-ish is. Nor MWS. Maybe you can explain?
-Carnac