Yes, you can have same servers part of separate server pools, however once server1 in pool1 is assigned then it can't be used again when assigning service profiles. This is done through a "Qualification" process.
Why you might do this? I'm taking this right from the configuration guide..
A server pool contains a set of servers. These servers typically share the same characteristics. Those characteristics can be their location in the chassis, or an attribute such as server type, amount of memory, local storage, type of CPU, or local drive configuration. You can manually assign a server to a server pool, or use server pool policies and server pool policy qualifications to automate the assignment.
If your system implements multi-tenancy through organizations, you can designate one or more server pools to be used by a specific organization. For example, a pool that includes all servers with two CPUs could be assigned to the Marketing organization, while all servers with 64 GB memory could be assigned to the Finance organization.
HTH
