Smith is just as "low-motor" as Suzuki, except he plays higher up the ice knowing he has Leonard covering for him, which I'm pretty sure is by design having watched at least 20 NTDP games by now. Whoever is the first man back (most often Leonard, sometimes even Perreault) spends the remainder of the defensive shift as the C.
I also think Smith's forechecking is being overlooked. He forces a ton of turnovers by taking great angles, having excellent timing and anticipating play, on top of having a really active stick and solid hand-eye coordination. A big part of the reason that line is able to have such sustained OZ possessions is Smith closing down on defensemen and forcing them into turnovers before they can find the right outlet.
Leonard forces a lot of turnovers on the backcheck and in the DZ, but Smith has the best stick in the OZ and NZ. I do think he ends up on the RW though.