The union site
The public site, backed by Strapi. It is deliberately the same in all three Options: what changes is where an Editor writes it.
Campaigns 4
The same campaigns, held two ways. What differs is what an Editor does in the admin, not what a reader sees.
Model A
each Tab is its own entry, with its own list of Sections
Model B
one entry for the whole campaign, with the Sections for every Tab in one list