is DLF flag = deletion flag?
if yes, then this does not play any major role for sales order archiving.
I would never split archiving by with and without deletion flag.
This creates 2 archives, a huge one and a very small one, but what does it actually tell you when you search a document in an archive later?
I split archiving in SD usually by sales organization
and if that is still to much documents in one organization then sales org in combination with document type or together with a date range.
This way you can easily describe your archives and the user can quickly find the right archive to look into, especially if you do not create permanent indices.
Of course I have more than 20 different variants.
you should define your variants in a way that they do not overlap, if you want execute them in parallel and if you do not want to confuse the people who may search for a document later based on your archive description.
Is SD_VBAK the first archiving what you want do? You will probably not have much success as the sales order is referenced in the delivery, hence you need to archive the delivery prior to the sales order, and the delivery is reference in the billing doc, hence billing doc has to be archived prior to delivery
Please click the network icon in SARA after you have entered SD_VBAK, SAP will show you what you have to archive earlier.