each race has its own sort of "capital" where the difficulty is higher than other cities its best that you try to take these over first Undead: Dead Plains Human Alliance: orthshire Men Of The West: Mylen Night Elves: azzitha Orcs Of The South: nartoth Wood Elves: eastern forest Mountain Trolls: Battakka Orcs of the North: thareth I usually try to attack the Undead, Human Alliance, and Night Elves capitals right away while their difficulties are still low then i watch the demons territory and attack them before their difficulties go up
an easy way to get double charges is to clear the battle field of both your units and the AI's units let the AI continue to spawn enemies wait until more than 10 are on the battle field and they are about to reach your side and call in the charge it this works best with giant trolls because of their health and damage