Mac user here. Similar setup different capacities similar models.

I have an M1 a 2018 and a Mpro 2013.

2 thunderbay4 type enclosures (Akitio thunder 3) on the M1

1 Thunderbay4 TBT2 and a Lacie Duo raid dock on the 2013 Mpro.

I use the 2018 with its 4 port TBT3 ports as a 40GB switch between them plus as VM machine. This also gives me 2 more TBT3 port for networking or expansion.

If you can afford it use soft raid. The other good alternative is using ZFS. I currently use it.

If you want more details let me know.