Really don't know how xp works, i'm afraid.
Good archers are valuable in strat. BUT, there's way more melee slots than range slot, so if you can't make a name for yourself in archery, i'm afraid it'll be quite hard for you to get hired.
The good players with the best k/d (and thus favored in strat) are arbalest dedicated users. Quite often, there's an heavy armor for melees, and a light armor for archers or the wandering backstabbing melees. And most of the times, that armor is just not enough to ensure your survival, were you hit in the body by a MW arbalest.
Archers are great for taking out quickly construction sites and other things such as catapult, where a good rate of fire is more important. But i don't think there's more than 10 range in one full roster (50 people or so), out of thoses, you can find 3-4 dedicated xbows, and 5-7 archers.
If the defending team (in a castle) gets too much range, they'll have problems dealing with a good dedicated melee weapon surging out of the siege tower.