It really depends on how close your nearest neighbor(s) are. If they're close, a very early archer rush can make a lot of sense (although luck plays a major role in how successful it will be). If they're a long way away, it generally makes more sense to focus on building up your economy first and fighting later.
An ultra-early rush with only two cities is quite possible if a neighbor is close enough. Two cities don't provide enough free unit support for a sustained campaign, but they can provide enough punch to cripple an opponent if the RNG doesn't hate you too much. One option is to do an initial strike with two cities, make peace, build a couple more cities and additional troops, and then strike again when the initial peace treaty expires.