The thing isn't that Earth Elemental is -bad- its that you can pay less for better creatures. Iron Golems or Devouring Jellies and so on will get more work done than an Earth Elemental for less mana AND less spell points. So, by comparison EEs are terribly inefficient.
As far as Warlord answers to Earth Elemental-
-Grimson Deadeye sitting on a watchtower can plug 3-4 attacks into it before its even close enough to attack. (4 dice from 3 zones, 5 from 2, 6 from 1)
-Thorg can waste an Earth Elementals turns but taunting it and forcing it to move to his zone (since its a slow creature with no quick attack it will just uselessly lumber around)
Hit it with Quicksand to force the opponent to spend actions to free it or spend his teleports.
-Use Stumble and/or Fumbles to waste its attempts to move or attack while youre creatures burn it down.
Reverse Attack while Grimson or any other hard hitter focuses damage.
EE has no armor, so as long as youre running a few ranged creatures you should be able to burn him down easily before he can do much damage especially if combined with aforementioned tools to hinder its ability to move (quicksand/stumble) to buy extra rounds.
Stumble / Fumble don't work, because the EE is unmovable.
Quicksand will cost you 10 mana and therefore a complete turn. If you decide to kill the EE, I think the strategy should be to do that in less than 2 turns with less than 20 mana. Otherwise the other mage gains on you.
Also, the EE has a nasty Daze/Stun.
Of course I understand the global concepts brought forward in this thread (ignoring, flying, guarding, take hits, ranged attacks), but I have not seen a post showing how to kill the EE in 2 turns with 20 mana invested at max.
I would suggest maybe opening with a Barracks and Garrison post so you can at least start spitting out creatures.
Typo?
I'll see if I can post my book.
I find the iron golem much better. 6 dice, only 13 mana, psychic immunity, also unmovable.
An Iron Golem in average needs 6 attacks to take down an Earth Elemental.
An Earth Elemental in average does 3.5 critical dmg per attack and therefore in average needs 4 attacks to take down the Iron Golem, during which the Iron Golem is Dazed after 2 of these.
-Thorg can waste an Earth Elementals turns but taunting it and forcing it to move to his zone (since its a slow creature with no quick attack it will just uselessly lumber around)
Elementals are psychic immune so they ignore the taunt.
-Use Stumble and/or Fumbles to waste its attempts to move or attack while youre creatures burn it down.
Those spells don't work on unmovable creatures such as EE.
Psychic Immunity only for non-lvinging conjurations, not for Elementals?
Important: Unless the card says otherwise, all conjurations have the following traits: Nonliving, Psychic Immunity, and Unmovable (you can look these traits up in the Codex).