Within a WS, you cannot have a folder of the same name.
I would go with something similar to what Jesus posted:
Business Unit (often a workspace)
Region
-Archive
-YYYY Channel
--YYYYMMDD - ProgramType - Descriptive Name
You can add a region code to your Programs, but not always necessary.
Program Type could be a code like "WB"
The date on a Program is always the intended launch date; the exception might be a Quarterly or Annual Program like PPC.
Sub Programs, Campaigns, or Assets can be a descriptive name, in folders like so:
Flows
--01 - Invitation
--02 - Registration
Emails
--01 - Invitation
--02 - Confirmation