When you have a city the size of San Francisco, more than one assembly of Believers is not schismatic. Also, the case maybe the other Gospel preaching church is not of the same faith and order, say its Orthodox Presbyterian or Free Methodist.
I don't imagine there are too many Christians in San Fransico to fit into a single building, firstly
The gospel is what unites Christians, not secondary issues of doctrine. We are never told to separate over anything other than gospel issues, quite the opposite, in fact.
Finally, cities have sections/neighborhoods, and those would be fine names for churches once a church is maxed out.