I don't think Trippier *can* fully replace Walker - too different in terms of playing style and physical attributes (reasonably quick but nothing special versus lightning fast - short and somewhat slight versus built like a brick outhouse, and so on). Ditto KWP. It will mean adapting our play to compensate, and whether that's wise is an open question given that the previous system saw us get 86 points and a runners-up place.
On the other hand, signing someone like Toljan (who can play on both flanks), or Pereira (who can play and actually prefers playing as a winger) could lessen the need to make that shift, and given their versatility, would still allow us to spread our talent evenly across the squad instead of being overloaded in one particular area.