To help you with your move to Cloud, we use best of breed modelling tools to build enterprise or ecosystem data models; map existing assets; and assess the impact of new policies or projected changes to models, databases, or data fields.
Our preferred tools are Idera and Erwin.
Data models for ecosystem or enterprise do involve consistency of terminology so that there is a shared & standardised vocabulary and understanding of data descriptions, and therefore data structures. This is particularly the case if the mapping leads to a data catalogue.
But, if you intend to model, you have to be able to extract the metadata first and not all extracts translate easily or accurately into modeling or data dictionary packages…