I'm a fan of the sushi principle: raw data is better than cooked data.
Each process should take data from a golden source and not a pre-aggregated or overly normalized non-authorative source.
Sometimes the role of your system is to be the authoritative source of data that it has aggregated, validated, and canonicalized.
Sometimes the role of your system is to be the authoritative source of data that it has aggregated, validated, and canonicalized.