MDG-F Data replication for CCH using IDOC

Hi

Can anyone explains differance between Cost Center Hierarchy and Cost Center Group in MDG? As per my KX CCH in MDG is Alternative CCH in ECC not Standard CCH in ECC as it is created in Customization for Controlling Are.We can able to create alternative CCH in MDG with single processing also but when trying to replicate in ECC

SLG1 logs says as per below

Here it says CCH uses SOA but we maintained IDOC,Is CCH replication is not possible through IDOC with message type COGRP1.

Secondally we maintained ZG replication model but it says DIRECTLY replication Model . Any Clue?

Also how to assign MDG alternative hierarchy to ECC Standard Hierarchy node in MDG or we have to do it in KSH2 only from ECC side?