ok here is what i think you should do, use the current age of mythology (my fav. game and im doing maps from there ^.^)
all models are in game that can turn into age of mythology, maybe only little missing,
Greek:
Cyclops: the orge with one head and one eye, its already in the warcraft world edit
Medusa: naga witch, can be used as Medusa
Hydra: the hydra already in map

but its kind of imposoble to make it the same as AoM
Carcinos: you could use the crab in the warcraft, just change the color and size

Minotaur: there is a model already in the hive, not a big size also

check that out
Centaurs: use the archer one from warcraft, its the same ye?
Colossus: use a um, dunno you ask someone to make you a custome one or, just use the war golem
Pegasus: there is a model in the hive

Manticore: you could use um, a custom model that matches this, or i think there is one alike :S cant remember
Nemean Lion: just find a lion model

or ask a request

Chimera: ask for a custom model

Scylla: a water hydra that cant walk on ground, change the ship model into hydra
Egyptian:
Sphinx: custom model

Wadjet: there is a model in the hive called serpent, its a bit similar
Anubite: there is a model in the hive called son of something i forgot -.-
Petsuchos: epic if someone did it for you

Roc: easy model for a modeler i guess :S
Scarab: there is alredy a model in the world edit, called scarab i think, its the narubian insects, just change it color try to make it gold like the one in AoM

and size
Scorpion Man: epic if someone did it for you :O
Mummy: get a zombie from warcraft

or if you really up for it tell a modeler

Avenger: another epic unit ^.^
Phoenix: there is a phoenix in here already

Leviathan: a big fish that can transport :S MODELER WERE ARE YOU?
War Turtle: use the turtles in game, the giant turtles in warcraft

(war turtles i think)
Norse:
Raven: get creative

Valkyrie: there are some models in the hive of a spearwoman on a horse

Einherjar: find a dual sword unit in the site

Troll: a customized troll in this site or just use the basic one in the warcraft

Frost Giant: there is a kool skin in the hive that can help you

Mountain Giant: use an two eyed ogre, i think its the ogre lord something like that
Battle Boar: get a fel boar, try to make his colors as gold
Fenris Wolf: take a frost wolf, it suits it well

Fire Giant: you could use some skins in the hive or some cool models, or use the Fire Lord from the warcraft units, what ever you like

Kraken: if you can find a model or a modeler who can make this, im in your project

Jormund Elver: no idea how you could make this, but a modeler knows

Nidhogg: modelers to the rescue
Atlantis:
Promethean: use an ogre or orc with the skill of the hydra

(the one when dies turns into smaller units

)
Automaton: find the unit in hive, named arcane knight, matches this unit, make them heal ONLY each other and revives each other
Caladria: a flying scout, i dont think you need this
Behemoth: a weird looking bug like myth, good at taking out buildings, model i guess
Satyr: you can take the current ones in the warcraft, i forgot their names, but they look exactly the same
Stymphalian Bird: a flying bird that hits arrows....
Hekagigantes: if you can ask for a 4 armed ogre or monster, thats him

Argus: a flying octopus that spits acid....
Lampades: a crazy witch

Servant: a water unit that looks like gene
Nereid: satyr riding a dolphin, that makes it a water unit
Man O'War: a water, giant looking octopus but in water
Just by writing their names for you i got millions of ideas

these are all mythological units for Egypt Greece Norse and Atlantis

Have fun
GODS:
Greek:
Zeus: King of the Gods (lighting and the skies)
Poseidon: God of the sea (Tsunami, Storms and Seas)
Hades: Lord of Erebus (death, underworld, ghosts)
Norse:
Odin: Thor's Father (units, ravens, and spears)
Thor: God of thunder (dwarfs, gold mining, weapon forging)
Loki: God of Evil (darkness, destruction, betrayal)
Egypt:
Set: God of the darkness (animals, taming, obelisks)
Isis: Queen of the Nile (food, gathering, cats)
Ra: Gof of the Skies (eagles, peace, sun)
Atlantis:
Cronus (AKA Kronus): Lord of the Gods (transportation, death, evil)
Gaia: Mother Nature (trees, animals, springs)
****: God of **** (forgot sorry D
Sub-gods:
Greek:
Athena - goddess of spear and battleship
Aphrodite - goddess of beauty
Hermes: god of messengers
Ares: god of war
Dionysus: god of forging
Apollo: god of the sun
Hera: queen of olympus AKA goddess of whine
Hephaestus: Creator of man and fire
Artemis: God of destruction
Norse:
Freyja: god of war
Forseti: god of war II
Heimdall: god of warship
Skadi: Goddess of winter and hunting
Njord: God of the seas and storms
Bragi: God of Blacksmith and War III
Tyr: Lord of the Wolves
Hel: Goddess of evil and keeper of Hell
Baldr: Keeper of heroes
Egypt:
Ptah: god of the sands
Bast: goddess of the moon
Anubis: God of evil
Hathor: God of plague
Nephthys: Goddess or God (cant remember) of Death
Sekhmet: Goddess or God (cant remember) of fortification
Osiris: God of balance and judgment
Horus: god of the wind
Thoth: God of rights
Enjoy

*need anymore info just send me a message ^.^*