When I deleted all those armies, I was bringing in over $253,000 gold. Also note that with every ritual you start/complete, your relations with Dark Elves, Skaven and Lizardmen will get a permanent negative qualifier, while you will get a positive qualifier with other High Elf factions.
Throw in some Phoenix Guards for Anti-Large and Eagle Claws for Artillery support.
This means not breaking treaties too soon after making them (10 turns), or attacking too soon after ending a treaty (10 turns). They are not in Ulthuan (High Elf Island) but are close enough that you can get your Nobles to them in a few turns to start farming. Elven armies can enter the Use Worldroots stance to use the Worldroots. They are squishy until you max their Armor and Melee Defense skills and get Student of Hoeth.
As someone else said above, this is totally not in line with the spirit of Total War and Warhammer. A special resource which is required to recruit powerful units, and to upgrade the Oak of Ages.