Thanks for your replies Nathan, Santosh. We had difficulty assessing this benefit because apparently, there's an issue with our sFIN with the ANEP table not being deactivated (it's supposed to be deactivated and redirected to a CDS view in sFIN already). This made us jump into wrong conclusions that there's no difference in terms of postings between an sFIN and a non-sFIN system as there are still postings in both AA and GL tables. If you're interested about this issue, the symptoms are described in SAP note 2182930 though the solution didn't fix our issue, so we'll reach out to SAP about it.
Now we have found that postings for group assets are "redundancy free" because postings will only be made in ACDOCA table -- no postings in AA tables anymore.