Communication between golden model and DUT

in protocols like ethernet
if iam going to test this protocol TRANSMITTER “TX”
should i test mac"part of data link" separately with a specific model for it
and when iam done from testing i take the output of the RTL of the mac " already verified as mentioned above " and put it to the model of the phy i made and the RTL of the phy
is this case valid in verification or not