If I can add a comment that I did not notice yet in the thread, if the map type allows to settle coastal cities, using cargo ships instead of caravans is completely broken. It's somewhere around +8 food instead of +4 for a mere 25 extra hammers.
Absolutely. I forgot to tell about cargos but the evidence is clear. If you can build a cargo for food instead of a caravan, just do it.
Is there any reason you're pushing food pre-aqueducts?
What you would do instead? I find the early food caravans the best way to enhance other cities to make them productive and populous(especially when they have finished libraries) and recuperate faster in term of science and military. When you hit education and artists building you can run 4-5 specialists early without crippling too much the overall growth.
Having 10+ cities by the turn 90-100 is the actual mid term goal of this strategy.