In one-arm mode, do my pool member servers have to be in the same network as the vIP/self-IP?

Reading through the LTM Implementation Worksheet and it says:

 

"In a one-arm network, the Virtual IP (VIP) is on the same IP address space as the pool member servers. A one-arm network typically requires the source IP to be SNAT'ed to the floating IP address of the LTM when the packet is sent to the server. In a one-arm configuration, the server's default gateway is a network device such as a switch or router."

 

Is this the only way or can I have my pool members in a different network/subnet as my self-IP and vIP?