MDG-C: how BP roles are mapped to CRM ?

In our company we are starting with "MDG for Customers implementation project" and I'm trying to understand how integration between MDG-C and CRM will work.

In ECC the standard defined BP Roles are different than those in CRM

(ECC: FLCU00 - FI Customer, FLCU01 Customer and so on, but in CRM: CRM000 Sold-To Party, CRM002 Ship-To Party etc.)

Should the CRM BP Roles definition be copied to MDG-C (ECC) system? Or there is some mapping to be configured? I was trying to find some documentation - but there is noting on this particular topic.