The real important stat in these games is DPS (damage per second). If the units have different rate of fire, it should be shown in the unit stat.
Read elsewhere on this forum that longbowmen have a much better rate of fire than other ranged infantry. This should be the reason why massed longbows early in the game (age 2 or early in age 3) are pretty hard to counter and are by far the best costwise unit of the game.
I suggest 2 things for Es :
1) if it is true that the rate of fire of various unit is not always the same, include the rate of fire in the statistics showed ingame.
2) increase the price of the longbowmen (would be realistic as they were very long to train compared to musketeers and crossbowmen).
The second sugestion makes sense (if a given unit is much better than all others costwise, there is not much strategy left. All brits players will mass longbows which was realistic in the AOK era, but not in the AOE3 era).