I think there are too many permutations that have to go the specific way for Sione to both stay in (or come back to post Japan) Australia and become first or second choice IC for Wob selection. My gut feeling is he would be perceived the same as Paisami, strong in what he does well (i.e. midfield carries and offloading) but seen as both limited (not necessarily been instructed or encouraged to develop his short kicking/passing game) and a strong tackler but not "defender".
NH Rugby isn't kept up with much here, but up until the '23 Six Nations, was probably seen as 3rd Choice at Both IC (Behind Cam Redpath and Sam Johnson) and OC (Behind Huw Jones and BIL Chris Harris),. Hell, in his first Glasgow Season he probably wasn't guaranteed a starters jersey when fully available: Johnson was the nailed down IC, and he was competing with the likes of current Captain Kyle Steyn and ex Scotland International Nick Grigg for 13.
I got a touch off topic I think. But thinking "we need a big piss off ball carrier" is a somewhat limited way of thinking, both in what you want from that position in the team and that player as an individual.