Beware of youtube videos about connecting 2 compressors together

This is interesting. In theory, would the CFM capacity of the compressors be additive? In other words, would two 10cfm compressors provide 20 cfm in this configuration?

Also, is there a good schematic out there that shows the dummies like me how everything is actually connected? Or is it really as simple as running the two motors off of the same pressure switch, so when the tank comes up to pressure, it shuts them both off at the same time?