Nick Mallett's core argument is that the Kolisi vs De Villiers debate is somewhat misframed — they're contrasting operators at six, not direct replacements for each other. Kolisi is the concrete mixer: dense, direct, a counter-rucking presence. De Villiers is evasive, a natural poacher with elite body positioning over the ball. Mallett likens the dynamic to the long-standing Kolisi/Kwagga Smith complementary pairing, suggesting De Villiers could fill that finisher role rather than simply usurping Kolisi's starting berth. But the warning is pointed: Kolisi needs a strong showing against Argentina, because Rassie will not keep quality youngsters on ice indefinitely. With the All Blacks series looming, Mallett says it's 'squeaky bum time' for the older generation — depth is only an asset if it's actually deployed against top opposition.