LA Ermor is (unsurprisingly) very narrow. Probably the most narrow in terms of pretender design even: you have to take several death magic points (anything below 4 is pretty suicidal) and an awake pretender, as a sleeping pretender *will* get you killed. fast. A strong dominion is also, while not absolutely necessary, still very important.
Also, for late age your national troops (read autosummons) plain suck. And getting priests with high magic to cast those whole-battlefield undead buffs is quite expensive, better summons are more economical. A bless will also be wasted on Ermor as you'll only get decent amounts of decent blessable troops quite late. (and good priests are still expensive)
Also, they lack several hundred coolness points because they're restricted to lame zombies and skeletons instead of the awesomeness of ghostly roman legions.

Tien Chi MA are very diverse. And you'll have to utilize that, as you get comparatively wek mages that have lots of different paths to make up for it. You also get a nice mix of national troops and summons.
Also unsurprising, since MA Tien Chi is basic Tien Chi from D2. Though a bit better imo.