You are experiencing a different breakdown than I am.
If 3 people are on a roof, 2 of them are xbows. Why? They can use the roof to hide long enough to load.
Archers are more mobile, able to move with the infantry easier than a xbowman can. Archers are much more likely to be found running to find an unawares group on their flank where their shields are not directed.
So quit talking about roof camping archers. They are much less common than the xbow on a roof, and they wear paper armor and are an easy kill. It is the roof camping crossbowman with heavy armor that takes several hits to bring down that are an issue.
No, there are a lot more archers than xbowmen on the roof, and archers are a lot more dangerous because of their rate of fire.