Hello there, I've been running a Horde deck for a little over a year and a half, what I've figured out are:
cards that need to hit are awkward so things like Ashling, the Extinguisher aren't great you also have some big creatures that are just big and you aren't running enough things that give trample, so things like Chameleon Colossus, Doomgape, and Lord of Extinction have problems hitting. Trample is good.
Your also deficient sac outlets, to abuse Horde you need your stuff to die. I'm a big fan of Phyrexian Alter, it gets you infinite mana with Avenger of Zendikar. I also like Magmaw. Your Skullclamp is a sort of a sac, how consistently do you get a toughness 1?
your Equipment is good but i recommend things that buff Hordes to a 7/7 so the swords are really good, Behemoth Sledge is good and Champion's Helm is good.
1 Horde of Notions
Land
10 Original Dual Lands
10 Shock Lands
10 Onslaught/Zendikar Fetch Lands
2 Forest
1 Island
1 Mountain
1 Swamp
1 Cavern of Souls
1 Krosan Verge
1 Reliquary Tower
Creatures
1 Flamekin Harbinger
1 Fauna Shaman
1 Smokebraider
1 Animar, Soul of Elements
1 Eternal Witness
1 Flickerwisp
1 Fulminator Mage
1 Incandescent Soulstoke
1 Mirror Entity
1 Splinterfright
1 Trinket Mage
1 Wispmare
1 Chameleon Colossus
1 Forgotten Ancient
1 Oracle of Mul Daya
1 Genesis
1 Ingot Chewer
1 Karmic Guide
1 Lord of Extinction
1 Magmaw
1 Mulldrifter
1 Reveillark
1 Seedborn Muse
1 Shriekmaw
1 Silverglade Elemental
1 Skullmulcher
1 AEthersnipe
1 Soul of the Harvest
1 Vigor
1 Avenger of Zendikar
1 Doomgape
1 Faultgrinder
1 Gaea's Revenge
1 Hateflayer
1 Regal Force
1 Maelstrom Wanderer
1 Enlightened Tutor
1 Mystical Tutor
1 Swords to Plowshares
1 Worldly Tutor
1 Crib Swap
1 Mortify
1 Putrefy
Sorcery
1 Green Sun's Zenith
1 Demonic Tutor
1 Life from the Loam
1 Buried Alive
1 Increasing Ambition
1 Traumatize
Planeswalker
1 Jace, Memory Adept
1 Liliana Vess
1 Garruk, Caller of Beasts
Artifacts
1 Skullclamp
1 Sol Ring
1 Illusionist's Bracers
1 Lightning Greaves
1 Chromatic Lantern
1 Phyrexian Altar
1 Rings of Brighthearth
1 Birthing Pod
1 Survival of the Fittest
WUB Sen Triplets WUB
WR Jor Kadeen WR
WUBRG Horde of Notions WUBRG
UBG The Mimeoplasm (MTGO) UBG
BGR Kresh Eldrazi (MTGO) BGR
Legacy:
X Ravager Affinity X
cards that need to hit are awkward so things like Ashling, the Extinguisher aren't great you also have some big creatures that are just big and you aren't running enough things that give trample, so things like Chameleon Colossus, Doomgape, and Lord of Extinction have problems hitting. Trample is good.
Your also deficient sac outlets, to abuse Horde you need your stuff to die. I'm a big fan of Phyrexian Alter, it gets you infinite mana with Avenger of Zendikar. I also like Magmaw. Your Skullclamp is a sort of a sac, how consistently do you get a toughness 1?
your Equipment is good but i recommend things that buff Hordes to a 7/7 so the swords are really good, Behemoth Sledge is good and Champion's Helm is good.
Smokebraider is weak and you almost have the Lark combo just need something like Karmic Guide.
This is what I can think of off hand.
Horde of Notions