It should say Kane Linnett > Brian Smith because he was heading to Newcastle earlier in the year.
I don't see the comparisons to Best or Monaghan. He hasn't shown anything like their athleticism, footwork ... nor jumping ability, despite being taller than both of them.
He's gone from relatively unknown to "overrated" mainly because he has played on the left side outside Mundine and then Henry, along with a strong backrower in Marketo. The good thing about him is that he came through as a right centre and has handled playing on the left. He's a solid defender but not all that outstanding.
He's impressive among a list of fairly unimpressive centres heading the stats in the NYC, where average players are lauded depending on how much ball they get and how strong the team around them is ... they are galaxies away from the class of Croker, Wright, Idris, Vidot, Tomane, Gordon that stood out last year. Players like Foran, Whare, Griffin, Copley, Low are better centres.
Personally I saw Linnett drifting between centre/backrow and taking a long while to show his worth in first grade. He'll be a solid player in a strong team ... although a truly strong team would see him in the NSW Cup for a couple of years.