Also I just realised….those WD drives are Thunderbolt 2.
So I will need Tb2 to Tb3 adaptors. That past is not the problem, the problem is I don't know if it will work on the M4 Mac. Tb4 is backwards compatible with Tb3 but I don’t think it is to Tb2.
People who have the Ultra M2 cannot get it to work, not without some really silly work around.
Protocol-wise, TB3/4 ports are backwards compatible with TB2, any adapter should work.