The alternative batsmen appear to be only Bopara or Shah; Shah or Bopara. As has been said, both have had chances and not convinced. If Vaughan and Strauss are hanging on to their places and contracts because the selectors have no faith in B & S why don't they try some others? It can't do any harm. If they feel that Bopara and Shah are eventually going to make it, they should give them more opportunities. What's the point of keeping the old hands in the side and thus not giving these two batsmen a proper go? Fair enough, other players, e.g. Cook, have stepped in in an emergency and impressed enough to be given a permanent place. Shah and Bopara have yet to make convincing cases for themselves but they are still hovering around, neither in the side nor out in the cold and meanwhile none of the selectors are coming up with any alternatives.
I suggest giving the two lads a proper run in the side (both together or one at a time) and finding out if they are up to it. But this can't be done unless somebody else gets left out.