Greetings

I am investing in a new system.
(Ryzen 7 5800X + Ryzen 570 gpu)

The old system has a raid 10 array that I would like to put into the new system.

The new system is going to add 2 M2 drives that I want to set up as raid 1
and this is for use for /EFI, /boot, /, /var, /usr and swap.
There are 2 2.5" SDDs that are going to be set up as raid 1 for /home.
Want to be running Devuan daedalus.

The idea is to transfer the previously used drives from the old system
into the new system.

The question:
is it better to load the system and then add the hard drives

or

do I move the drives into the system and then install the system with
the drives at the same time.

(2 step process or 1 step process.)

Any gotchas I should be aware of - - - have not ever installed AMD
procs nor gpus (want to run the open source drivers and will be quite
happy to leave the nvidea world behind).

(If further information is needed please advise.)

Regards

Aj