hmmmm, interesting.
Kevvie must have been coaching Turpin his whole career. because he's never shown the ability to be anything more (at least in the NRL). his biggest attraction was always that he wasn't Andrew McCullough, but once the rose coloured glasses are gone, it was plainly obvious that he was Macca.
If it's true that Kevvie instructed him to be a tackle bot (and i have no idea one way or the other), maybe it was a case of a coach realising Turpin sucked at pretty much everything else, so got him to fill a role in the team by playing to his only strength