It seems as if developers from SAP had been forgetting two orgvalues when establishing the authorization concept for SAP EWM.
I recommend defining the following two permission values as orglevels:
/SCWM/ORG and APO_LOC
This is achieved by report PFCG_ORGFIELD_CREATE
As a result, within all dependent roles, the values can be maintained via the orglevel popup and thus a proper role derivation shall be possible.
Permissions: orglevels for SAP EWM