One of them will still need to be in the three behind the forward at the very least (to offer us some playmaking ability there), but otherwise, spot on. Berahino in Lamela's position yesterday on that five-on-three breakway wouldn't have dragged it wide of the far post in a botched cut-back/shot attempt, he'd likely have gone near post like trur strikers tend to do. That 'pure' goalscoring instinct might be what we need popping up in those positions from time to time, as opposed to Lamela/Eriksen's focus on playmaking. Son might be that player as well, of course, but to my eyes it looks like he's also trying to be a playmaking inside forward as opposed to an out-and-out goalscorer.
Yep, that's what I was saying -- play one of Eriksen or Lamela, then Kane and another forward (such as Berahino). If we don't sign anyone, then perhaps give Son a run and see if he can give us more cutting edge.