I say yes... at least one of them should be on the hot seat. Barring a turnaround, I think this should be 'it' for one of them if not both.
Either Dungy is not the coach to make Polian's vision work... or Polian's vision is not giving Dungy the horses he needs. Unless we make the Superbowl (or at least a deep playoff run and are a tough 'out') then I think Irsay needs to be having some long talks with these guys and see who's story he buys (if either) and then acts accordingly.
Why... why not?