The replay isn’t staged; it’s taken from a real online game. The player controlling the Barbarians knew how dangerous Wingael’s troops were (they can move first and destroy enemy armies) and took some countermeasures. P.S. If you’re interested in the theme of “Elves under the control of a non-native hero,” try using a demon as the leader (Necromancers are not very promising due to their low attack stat and the low chance of getting the “Leadership” skill) or, at worst, a Warlock (even a Barbarian would be better than a Necromancer).