I saw some people on another forum getting none, even until 70/7 map. So we both simply lucky enough to get her from 50/5.
True, but on later stages there's only automata, dwarf, and Ifrit. So archer is kinda undesireable at there. The automata comes in pack, so AoE works wonders.
You need shitloads of tank and healer on 100/2 map, 1 Mage in general is enough