Does cubase support multiple audio interfaces concurrently?
On the Mac, that’s built into the OS. Just create an aggregate device that includes all your audio interfaces. That will work for any DAW, including Cubase.
Whereas with a PC you need to use a 3rd party driver which has this ability built in, such as ASIO4ALL.
Mac or PC using more than one audio interface at a time will result in a higher latency (which may not be a problem for some uses).