That is a painstaking and methodical way of getting matches into order and under control.  I'm sure it helps if, like most of my tree, the people concerned do everything in the right order and keep things open and above board. But what about the others? 

My biggest Ancestry match is a total mystery, her tree (her version nor mine) doesn't match mine in any way and she doesn't answer my dms so I'm reliant on our shared matches.  The next biggest shared match has no tree at all, provides no clues and doesn't respond either.  In all there are around 27 shared matches and those with a tree, however small, generally give a hint at how they share with each other - the same surname in the same towns - but not with me!  
Obviously I'm looking at illegitimate births now but if one parent isn’t ever acknowledged there will always be some matches that won't be explained. And if this is back in the dusty past I'll never prove a thing.  And they all stay in that box marked 'annoying mystery' 
 
 