You can always find an example where the player comes in for a couple of years and helps a team win a flag, but there are plenty of examples of clubs getting players at their peak and then paying them lots of money to watch them decline. Eventually they player retires and there is no replacement because the club gave up draft picks 3-4 years earlier to get the player in the first place.
Getting a quality ten year defender sets up our spine for a decade. With Tom Boyd and a Stringer our forward line is looking ominous for a long time.
It's interesting though how often first and second year talks get injured before overcoming those injuries. Boyd, Patton, Hogan, McCartin, Moore, Daniher have all missed but chunks of there first two seasons with soft tissue injuries- is there a pattern here?