[Rytek]

For MA TC trolls kings (the W and E ones) are your first goto SC capable of stopping any sized AI army(excepting banes/banelords which you may not have the D income or paths for). All you need is conj6, cons 4 and alt 3. You can split the troops and put them in your army to add real backbone while creating a SC that can kill anything the AI can put together. Just one casting of the E king and one of the W troll can totally turn the war against 3 or 4 mighty/imposible AI's that have multiple armies attacking. This comes Much earlier than the army buff spells in Alt line. It is totally feasable to have 55E and 55W gems and the casters to cast them. Where they shine is killing off large AI armies sieging your forts. Send in the troll king against the AI army and use your smaller armies to cut off retreats.

Seriously, by the time you are casting Armies of lead the ai has already been defeated. Trolls come much earlier and for nations without SC they can can come at a much earlier point in the game when it is critical to be able to deal with the armies of 4+ impossible AI's rampaging thru your lands.