I'm sorry but "viewing documentation yourself does mean certainty - in a lot cases it only creates more confusion.
Much of early documentation was handwritten based on info supplied by humans ...and if there a lanuage difference, even more errors crept in.
For example the Church burial resistry can list a last name spelled Hagman and the gravestone in cemetery next door and see the name spelled Hagman. The death certificate has it spelled one, birth records have it the other way.
On the other hand, viewing original documents can provide additional information not included in digitized records and indexes.