Quickest way to victory I've found is putting an Easy computer on, Queen of Thorns or some such business, put it on
-Conquest
-Level 20/High Gold/Filthy Rich
-Low spawns/tower power, anything that could hinder your progress
-Increase game Speed
-Cataract
-Play Rook,
-Purchase Armor,
-Throw points into stats and melee, possibly health drain from structures in case the other DG decides he can maybe destroy you
-Destroy the enemy base.
-Game set.
I did it once to re-attain lost favor points (No luck there anyway)