We really have been spoilt with Kane, a striker who can do it all. Vinnie seems to have good scoring instincts, at least better for us than our other backups like Soldado or Janssen.
We aren’t going to be spending the money it takes to get better than Vinnie for a back up striker unless we luck out and get Daka or Eduardo for a good fee or get Ings and switch the system.
Kane is the issue, he is such a good player and when he is fit will always play therefore we need a player who every so often can come on and bag a few goals for a ok fee. Could we do better than Vinnie, yes but we could also easily do a lot worse and with our current state we would likely downgrade replacing Vinnie not upgrade.