That's pretty much how FA won his titles. He would happily sit 2nd to Schumacher without even a hint of an overtake attempt rack up the 18 points as it was, and then capitalise when the Ferrari had issues.
I think you've got your history confused. 2nd place was only worth 8 points back in the '05/06 seasons, and FA had kept coming home behind Schumacher in '05 wouldn't have won the title either. The McLaren was the fastest car that season but was a bit fragile.