Archers? Sure, especially if you're controlling a faction that lacks well armored, decent infantry and/or cavalry. It's obvious CA incorporated these ridiculously overpowered elite archer units to offset the heavy infantry of Roman, Greek and Carthaginian cultural factions.

On the whole I think archer units are overpowered in RTW. In fact, they are so overpowered that I find it hard to resist using them even when I don't need them! I am getting surprising if not crazy kill ratios with basic archer units in RTW, a stark contrast to the kill ratios I got with the average archer unit in MTW. Not that you couldn't have archers wreak havoc on the enemy in MTW but the results could vary wildly between battles and depended heavily on the types of archer units involved. It also doesn't help that the tactical AI in RTW has a tendency to do nothing when being rained on by your missile troops for an extended period of time. At least in MTW the AI would try to prevent attrition losses caused by missiles by closing the distance and rushing your main line.