RM puts a premium on swift resource ident. and retrieval, so the player would be wise to build as many villager as possible early in the game. Development is relatively slow, simply because of the need to get the stuff needed to go to another age or tech.
In DM the stuff is already there. The player should identify the strengths of the particular civ he's adopted, and rush to develop the techs and units needed to give full advantage to his civ.
I had Shang in alliance with Assyrians, but I fell to an alliance of Phoenicians and Babys. They managed to field a large number of priests, catapults and eles while I was still searching for their civs with a troop of scouts.
I should have known something was amiss when my nine scouts simply disappeared from the map. Not a good sign.