If your keeper generally comes in after the top order has seen off the second new ball (as Gilchrist has routinely been able to do) then pretty much any tom, dick or harry could be taught to bat well enough for a Test side: in most Tests it ain't THAT difficult.... something borne out by the improvement over their careers of Warne, Lee, Gillespie and McGrath, of Giles and Hoggard and of one Mark Richardson (from no 11 bat to opener).

What's needed from ALL the lower order is application: some will do better than others... and every once in a while the side is going to end up going from 5-out to all-out pretty quickly no matter WHO plays... but let's not hide from the need for the top order to bat through the better part of four sessions.

Bottom line: if you win the toss and bat first and your batsman is at the crease inside the first few minutes of day two... then no matter who is in your lower order... they are going to achieve a lot less than if they take over nearer lunchtime!