When to have multiple PASOE Instances, Web Apps, Services, a

I think I posted this to the wrong group yesterday (sorry for the duplicate):

I have a decent understanding of how each part of the PASOE stack behaves and is managed, but I'm looking for a simple explanation of when I should have more than one of any part of the stack. I didn't find a clear answer in the docs - rather, just the how-to-do-it part.

We are doing internal business development (not deploying to/for external customers) that includes multiple applications, each needing a set of Data Services/APIs that may or may not overlap with the other applications.

Instances - multiple for load-balancing. Ability to limit the load from one Data Service impacting performance of another Data Service? Other reasons?

Web Apps - multiple for different URL organization and different auth models?

Services - multiple services for URL organization?

Resources - this one is the most clear, essentially needing a resource for each "object" you want to work with via a Data Service.

And while you could put everything into a single PDSOE project and pick/choose what WAR files to deploy where, how do you split up your AppServer projects in PDSOE?

We have successfully used the PASOE stack for maybe a year, but are wondering if we need to reconsider some of the structure/organization.

Thank you,

Tim