Muktol

[[Lonely Sandbar]] or [[Barren Moor]] could be used as cycling lands.
Why did you use [[Mistvault Bridge]] and not e.g. [[Choked Estuary]] or [[Dismal Backwater]]? I couldn't find any benefit for an artifact land, only reason I can think of would be against land destruction due to being indestructible.

[[Poppet Stitcher // Poppet Factory]] would allow you to re-use [[Wilhelt, the Rotcleaver]]'s ability as the tokens lose all abilities (Decay), thus can attack and block and be reborn through Rotcleaver. [[Army of the Damned]] anyone with this combination? ;)

Personally I would reduce the mill part, keep only things that bring you advantage (like [[Jace's Mindseeker]]), and focus on the zombie part.

There are some cards that specifically strengthen legendary creatures:
[[Heroes' Podium]], [[The Circle of Loyalty]], [[Day of Destiny]]

[[Avacyn's Memorial]] (1$-6$) makes legendary permanents indestructible.
[[Robaran Mercenaries]] gets all abilities from your legendary creatures.
The flip planeswalkers from Magic Origins could be worth a look: [[Liliana, Heretical Healer]]
[[Teshar, Ancestor's Apostle]] or [[Yomiji, Who Bars the Way]] can help you to get some legendaries back from the grave after a board wipe.
[[Tatsunari, Toad Rider]]

Access to blue would be a cool thing, so you could add [[Leyline of Singularity]]. But sadly this doesn't fit your commanders colour identity.

What about [[Glory of Warfare]] and [[Sword of the Paruns]]? The sword might be a little bit out of budget tough.

A description of the decks strategy would be a good addition.

[[Battalion Foot Soldier]] would be similar to [[Legion Conquistador]]
[[Soul Warden]]/ [[Soul's Attendant]]/ [[Suture Priest]] could be used instead of [[Lunarch Veteran // Luminous Phantom]]
With a high number of creatures on the battlefield you could also take a look at [[Charge]]/ [[Inspired Charge]]

What about [[Shadowspear]] or [[Basilisk Collar]] instead of [[Lifelink]]? Both are equipments so you can reuse them when it's wearer dies. Shadowspear even would be from the latest Theros block. Only drawback is that they don't activate Heroic.

Other suggestions:
[[Heliod, Sun-Crowned]], [[Soldier of the Pantheon]] (Depends on the decks you're playing against), [[Staggering Insight]]

[[Alpha Authority]] could be an option to protect you enchantment carrying creature. Or the use of the boggles common in enchantment decks, [[Gladecover Scout]] & Co.
[[Ancestral Mask]] could be an option, tough you might only be able to squeeze in 1-2 copies of it due to it's price.
[[Kruphix's Insight]] could be worth a look if you need more draw.

"Waiting a round gives your opponent a chance to kill the creature (or EoV) before you get a chance to equip it."
He still has the chance to do so with a simple instant. He needs the mana for this in the situation but he still could do it :)

Toss a coin for your witcher ;)

[[Cast Down]] instead of [[Rend Flesh]]? An perhaps some dual or search lands to help you get the mana you need?

[[Trepanation Blade]] would buff a creature when attacking as well as mill your opponent a little bit. Drawback is that you can only mill your opponent and not yourself.

[[Cranial Plating]], [[Fighter Class]], [[Champion of the Flame]], [[Galvanic Blast]], [[Swiftfoot Boots]]

What about [[Joraga Warcaller]] with all the elves in the deck.

[[Urza, Lord High Artificer]] and [[Springleaf Drum]] are the most mana intensive cards you're playing, so you could perhaps cut [[Springleaf Drum]]. Question is if you prefer speed vs. consistency.

[[Etched Champion]] would fit the artifact/ affinity strategy. Else [[Tribute Mage]] or [[Trinket Mage]] could search you artifacts you need.
I would also include at least 2 [[Island]] in the mainboard as [[Blood Moon]] still will be around.

I would use more cantrips or cards with flashback, or you will run out of cards very quickly:
[[Reckless Charge]], [[Homestead Courage]], [[Defiant Strike]]

Other suggestions:
[[Festival Crasher]], [[Kiln Fiend]], [[Brute Force]], [[Lightning Bolt]], [[Expel]]/ [[Journey to Nowhere]]

[[Safehold Duo]], [[Safehold Elite]] or [[Bant Sureblade]]
[[Valeron Outlander]] as sideboard option against black decks

With [[Brass Squire]] in the deck you could go for [[Colossus Hammer]].
Instead of [[Shelter]] you could use [[Emerge Unscathed]]. Protection on this turn and draw vs. protection on this turn and protection (Unblockable) on the next turn.
As for the lands, most equipment decks I have built use 18 lands, tough with the peak at cmc 3 I would go for 20. Still gives you 2 slots you could use.
If you want to go for a second colour, take a look at red, there are some great cards to find (e.g. [[Champion of the Flame]], [[Reyav, Master Smith]], [[Galvanic Blast]], [[Shrapnel Blast]])

Else I can only suggest the more or less "standard" creatures and equipments for such decks:
[[Auriok Sunchaser]], [[Sunspear Shikari]], [[Stone Haven Outfitter]]
[[Cranial Plating]], [[Bone Saw]], [[Short Sword]]/ [[Honed Khopesh]], [[Bladed Pinions]]/ [[Cobbled Wings]] (Something I love, because it let's you weapon platform fly over your opponents defence)

[[Horn of Valhalla // Ysgard's Call]].... thank you, now I will have this catchy song in my head the whole day ;)

No [[Chittering Rats]]?

[[Vampire's Kiss]] drains 2 life and creates 2 blood artifact tokens. Helps to keep you alive and gives your artifact eaters fodder.
[[Makeshift Munitions]] is a weaker [[Orcish Vandal]] tough it's more versatile as it can also sacrifice creatures to deal damage.
[[Unexpected Windfall]] would give you 2 treasure tokens, but with 4 mana it may be to costly to add. Tough I think there is a weaker version for 2 mana that draws only 1 card and creates 1 treasure token.
[[Shrapnel Blast]] could be replaced with [[Galvanic Blast]]. The deck would loose a little bit flavour due to this, but you will gain 1 artifact that you can sacrifice into other sources.
Last [[Great Furnace]], [[Vault of Whispers]] and [[Darksteel Citadel]]. They are a little bit cost intensive ($) tough manageable, and could give you additional artifacts to sacrifice or count for metalcraft ([[Galvanic Blast]])