TOTD
Thanks for that it is all starting to make sense now and I accept that you will try to achieve it with the 4 crews, as you say it will not be easy and I feel will require some backup. Not quite the way crab portrays it at times. Just for info at present we operate with 4.5 crews that may change soon.
I also can't recall a time when in an emergency a second crew has not been found either when in the military or as a civvy. That is what we do.