To be fair, both Gilgamesh and Emiya-Archer aren't really what you'd think of when you say the word. I mean, both generally use weapons other than bows. Basically, every type of weapon aside from a bow. Archer generally either uses his swords or UBW, which is just a shit-load of swords. He does, sometimes, use his bow.....but to fire a Noble Phantasm in the shape of a lance. Gilgamesh doesn't use a bow at all, and he is Archer-class. He just straight up fires an endless amount of weapons of all varieties at his opponents.
Consider this, and the fact that Tohsaka had only seen Archer use hi