I always thought that archers were extremely effective in history. There are always stories of how english longbowmen tear apart the french knights, and how they win against an army twice as big as them thanks to their longbows. Plus i heard that a longbow shot can go through all that heavy armor that people wore those days.

As for in game, i think it's decent. Could be slightly more damaging, maybe up the casualties by a couple troops. I usually get a large amount of ranged units to shoot at not only the opposing archers, but the units behind them as well. And i like to do hit and runs with short-ranged light cavalry before we both start running out of ammo and send troops at eachother.