Page 3, catching up, yes, City elves don't know how to use weapons, those CE's DA2 were Qun recruits that was using bows.
Felya, they got training, which isn't given to CEs.
At the same time, its not hard to say they didn't train with sticks, which peasants have the ability to fight. They may not be as good as trained fighters though.
those that I have mentioned, one way or another, are all City Elves. CE aren't only the ones in the Alienages. CE are all the elves who lives in town with the Humans, don't follow the Dalish's ways, and usually are Andrastian.
Not all the Dalish are trained either. some are hunters, some are storytelles, some take care of the Hallas, some are healer or artisans. not all of them are fighters, just like not all City Elves aren't.
One way or another, even the Dalish Inquisitor is some kind of "special" case. S/he is a First, or a specifically trained warrior/rogue. Is not a common Dalish. Than even a CE Inquisitor would not be a common Elf. A bard apprentice, a spy, a newly recruited city guard or templar, a smuggler or a circle/apostate mage.
Thing is, there isn't really nothing at all that would make so "impossibile" a City Elf origin, beside time to work about it.