BTW, the Epic system allows one pilot to monitor Radar on his MFD and TAWS on his HSI whilst the other has TAWS on his MFD and radar on the HSI. Radar image needs to be optimised for the altitude (tilt) and sea conditions (gain) and that means that changes may be needed to the IAS/Altitude change. These changes have to be carried out by the PM.
This is essentially what the 139 FCOM says and that was the product of a lot of experienced offshore people at the factory and validated by those in industry.
Ultimately you have to write your SOP's and stand by them..... or not!
G.