Yardy is useful in that he ties up an end well, but he shouldn't be batting that high. Also he goes through his overs very quick, and it can force teams into panicking about run rate. Wright though for me offers very little, he occasionally gets a score through slogging but generally gets nothing. His bowling offers very little as well. As I said earlier, I think we have too many 'all-rounders' who don't really offer enough in either department.