Stock OpenSauce doesn't allow for multiple campaigns. There is a base for implementing a campaign which is composed of more than 10 scenarios however. Even still, it requires leg work to be done in the mainmenu (errr ui) as there has to be widgets implementing the user interface for the level selection and display.

Really, if a team wants to do any advance work with OpenSauce they require a programmer. A mod team will get no where in terms of adding new things into OS without a programmer. Find a programmer who is half way competent then lay down your ideas. Without one, you're just rattling off unbounded thoughts. With one, at least then you'll have someone to put a sense of direction and boundary on advance engine additions.