I bet that https://start.docuware.com/finance-and-accounting
is pure marketing stuff, i.e generic and depends upon the country and the way DW is integrated by whom.
For France I can tell you we did SAGE i7, X3 and 3000 (looks like it is specific for English market)
As written above, you need to know exactly what product line you are talking about.
Everything is called Sage something, but each line comes from various origin as Sage has bought a bunch of software houses.
Then you need to ask yourself what integration you want, sharing a data model ? adding some automatic export ? exchanging data using webservices ? Adding a tool so you can do real accounts and analytics splitting (not the tool from DW). We do all of that with inhouse developments using DW SDK.
Feel free to contact me if needed.