It is a stupid plan. Santorum should have already dropped out. Santorum basically gave Florida to Romney. There is no rationale for him to stay in except pride. Conservatives have not conslidated and thus they are facilitating Romney. No need to blame Rove, Rush or Fox News. It is a circular firing squad.
Romney still would have won Florida if Rick was out. Rick and Newt together do much better in the proportional delegate states.
I think that you are wrong. Newt and/or Romney can flame out at any time. If Rick or Newt can stay with the financial demands, they should stay in as long as possible. (I am a Newt supporter, but could support Rick.)