Decide how to utilize a slow and fast hard drive to install Ubuntu

Suppose I have to hard drives in my laptop, one is a (Disk A) classical spinning hard drive (or an old generation SSD) (<1GB/s) and the other one (Disk B) is a super fast NVMem SSD (3GB/s).

I. Suppose that they are not too big to hold everything. What of these options is better for Ubuntu?

1. Install / (system files) in (Disk A) and /home (i.e. userfiles) in (Disk B)?
2. Install / (system files) in (Disk B) and /home (i.e. userfiles) in (Disk A)?

It seems to me that 1) will produce a system that is fast for particular tasks happening in the home directory, but 2) will produce a more responsive system (e.g. booting, loading and running programs, loading libraries).

Is this logic correct?

Are there other combinations I am missing? (e.g. installing /usr in a hard drive different from /).

Suppose, for example and in addition, I do a lot of C++ compilation in this machine. Source files are read from both home and default libraries.