Ziebell needs to be replaced but would not be thrilled if it were by Corr or Perez. Corr is close to 30 and is average at best, and Perez has shown nothing at this level and has very little upside. Young or Dawson would be my selections.
It all depends on the structure of the defence. I think we have been developing the backline around personnel, not the other way around. While taking into account personnel traits is smart, it can't dictate strategy. Are we a 2 KP defending team or 3? Do we play an undersized 3rd tall instead (eg Bonar, Young, Jack). How much run do we need?
Not Jack's fault, but reckon he has affected the structure back there a fair bit.