Stonebrow's War Horde

Oh, I really like Stonebrow, have him in many decks. But as a commander? There are some things to worry about:

All he does is beefing your guys and you need tramplers for that. Which means you'll have an offensive deck with mostly fatties. An "honest" deck. In other words, a deck that will not do well against the typical streamlined EDH deck. Sure, IF you play against opponents that also run "honest" creature based decks, then you will have good chances. But even then you need to be careful with your mana curve and about the tricks your opponent will have.
EDH decks need lots of removal and denial to survive each other. Since your setup will be creature heavy, this means you need to put a lot of your removal and disruption on creatures, preferably ones with trample of course, but we won't always be able to do that. You have a few of them, like Spellbreaker Behemoth, but it's hardly enough. Most EDH decks run cards that would shut you down singlehandedly if you can't deal with them. Also, you run way too many expensive creatures without any form of mana acceleration (not even Sol Ring!?), which is waaaay too slow! And your fatties need to do something besides being big. Palakka Wurm and Borborygmos Enraged are good examples of fatties that are worth adding but guys like Craterhoof Behemoth are overkill, they don't add anything that you don't have already. Same is true for cards like Overrun, that's either "win more" or useless. Asceticism is good for this deck because it protects your guys and the hexproof part might even deny some of your opponent's defenses like Maze of Ith. However, what does Beastmaster Ascension add besides makin things that are already big even bigger? What is a bigger creature worth if it can't get past a Maze of Ith or it is dies to a Terminate?

With all of this in mind:

* I talked about creatures with removal, disruption and effects that hate popular EDH strategies. Here is a selection of creatures that will help you beating typical EDH decks while keeping up the high creature count and level of aggression:
- Hellkite Tyrant
- Kavu Predator
- Polis Crusher
- Skyshroud Warbeast/Wilderness Elemental (depending on if you using this for multiplayer or 1-on-1)
All the above have trampler, however, the ones I was actually thinking about don't:
- Ash Zealot
- Magus of the Moon (this might cause some players to lose instantly!)
- Burning Tree Shaman
- Bane of Progress (this is also a gamebreaker!)
- Reclamation Sage, Indrik Stomphowler, Acidic Slime
- Woodripper
- Vexing Shusher
- Tunnel Ignus
- Stigma Lasher
- Heartwood Storyteller
- Thrun, the Last Troll

* Avatar of the Resolute is strictly better than Garruk's Companion. However, you might as well keep the companion and cut one of the redundant fatties.

* Drum Hunter would be a very nice addition, it should provide extra cards AND it adds some much needed mana acceleration (even if that is slow). To make room I would cut the Wild Beastmaster. He is pretty worthless here since you a) don't beed more pump and b) it pumps others basing on it's own power, which is just 1.

* There should be a minimum of mana acceleration/ramp. At the very least Sol Ring but I would also consider options like Solemn Simulacrum. Even something like Cultivate will be very helpful.

* As I mentioned, in EDH there are lots of cards commonly played that render your entire plan useless, things like (Magus of the) Moat for example. The changes above will give you some options to remove those, however, that will not always work out. A nice way to deal that last damage when attacking isn't possible or worthwhile anymore is to just fling your big guys at the opponent directly. Fling itself is a card to consider but there are more:
- Bloodshot Cyclops (who is a fatty himself)
- Chandra's Ignition
- Soulblast (very risky because if it is countered or prevented, you have lost everything, but otherwise you have most likely won!)

* Is Quietus Spike needed? Your guys typcially neither need deathtouch nor additional damage that only triggers when they are doing damage - you need equipments that help your guys going through the defenses in the first place! There are so many great equipments out there for 3 mana, I think all of the Swords are each better than this. Of course, they aren't exactly cheap, moneywise. But still, I think something like a Whispersilk Cloak will serve you better, both against "honest" and "good" EDH decks.

* To my experience, almost every EDH deck makes use of his graveyard, this deck here being the exception. I would always run graveyard hate in my EDH decks.At the very least add Relic of Progenitus - it doesn't hurt you to lose your graveyard and if you don't need to exile opponents graves, just pop it anyway and draw a card to replace it!

* You'll need room for the changes, here is a list of cards I consider removing for the reasons I stated in the introduction:
- Overrun, Overwhelming Stampede, Beastmaster Ascension, Gruul War Chant (redundant pumpers)
- Craterhoof Behemoth, Pathbreaker Ibex, Decimator of the Provinces, Gruul Ragebeast (too expensive and redundant)
- Outland Boar, Centaur Chieftain, Godtracker of Jund, Grove Rumbler, Nacatl Outlander (don't do enough for their mana)
- All these changes will make the deck faster/cheaper, so maybe you can cut a land or two

* Depending on the selection of creatures you added and removed, you might end up with too few tramplers. In that case, add Brawn. In fact, you should run Brawn no matter what, replacing something like Centaur Chiefain. Same is probably true for his companion, Anger.