Can PUM server residing on virtual machine support multiple virtual environments. In other words, i

Can PUM server residing on virtual machine support multiple virtual environments.  In other words, importing multiple ova files onto one same virtual machine?

We are planning to set up PUM server on our Virtual appliance.  We know that for Oracle VirtualBox installed on physical server, it can create multiple virtual environments.  Given we're going with virtual server, can multiple environments be setup within one virtual server?  If yes, any idea on the hardware sizing requirement such as CPU, RAM and storage recommendation?  On the PUM homepage, it indicated for full tier of PeopleSoft, it'll be min of 6GB of RAM and storage of 100GB.  How do anticipate other apps (HCM, CRM, ELM, IH) sizing add ons?