Two reasonable pool usage scenarios. Most installations should be able to optimize performance with 5 to 8 pools. While some installations might ultimately use a few more pools, too many simply means a lot more administrative work. I think that 10-12 might be an upper limit on effective pool and object tuning.

Remember that the pools are a system resource. While segregating them on an application basis might be nice for the application, it is unlikely this approach will provide the most efficient usage of pool and memory resources.