I believe that the best way is to provide 2 separate areas.
1: dry area for the storage of seeds
2: more humid and warm area for the brood
Saying that, mine decided to nest in one place, then bring all the seeds close to the brood. Don't worry, the ants will sort themselves out and I've found that all of your best plans about what they will do and where they will nest go out of the window when the ants decide what they want. They will do whatever they please
my nest looked beautiful, followed instructions on putting stones at the bottom for moisture control etc, the ants decided they didn't like the stones there and piled them all in the arena, then dug most of the sand out too lol.