Thorn brought that old school philosophy that the referee was more a guide than a definitive authority. He had arms the size of Christmas hams and a glare that could curdle milk. Even Bakkies Botha would have been wary of invoking the wrath of Thorn.
Kaino was much the same - a line in the sand player who made it clear he was willing to accept and inflict pain in equal measure to carry out his job. In the World Cup semi-final both James O'Connor and Quade Cooper ran with caution - always fearful of where Kaino and Thorn may have been lurking. No one likes to find themselves in a dark alley with such uncompromising characters.
The All Blacks need similar characters to emerge this year - someone just a touch nasty to play the tight locking role is a non-negotiable. All eyes will be on Jarrad Hoeata when he returns to action on Saturday.
He seems the best bet to develop into a ruthless mass of controlled fury. He's got that natural desire to enforce himself on the game and check out the resolve of others. He appears the most likely heir apparent to Thorn.
Finding a similar beast to Kaino is going to be more of a problem. Adam Thomson is the best performing No 6 in the country but his game is different - he's a ball carrier, a runner and off-loader who is at his best roaming wide.
Victor Vito has the physical attributes to be a tight, crunchy blindside who sits people down in the tackle and lords it over them. But so far he's come across as too nice. Liam Messam is a glorious ball player but not an intimidator and George Whitelock is probably not test class.
The man with the most promise is Brad Shields - a bruising 110kg presence who at just 20 has found his feet at Super Rugby this season. It's early days in his career, but longer term, he's maybe the one most likely to replace what is being lost.