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Is the Poseidon campaign following the Zeus one or are they independent?

(that doesn't seem to be specified anywhere)
This question / problem has been solved by Neviskioimage
They have both a ramping up progression in campaigns, although zeus has a complete tutorial and the first campaign is a LOT easier than the first of poseidon.

I'd suggest to play the first atleast first campaign or atleast the first few chapters to get an hang on it, you'd have generally a good time better than on poseidon due to the first map of the first campaign be a bit of mess in terms of organization =P
dont forget to remember to leave some space in your cities, the game carries over your previous city to the next chapters , some times you will have to come back and do more stuff like raise appeal etc or build x gyms.

as you progress, find out the structures and techniques that grant you a army without much pain like depending on the population to raise one , you will need it badly in the later parts when your enemies launch a invasion every time or learn to counter the god threats by knowing which gods to have
Does any one know of a way to reset the tutorials? Mine seem to have installed as 'done'...