Quote ="Buggo"Australia fielded the Four Club Fullbacks in the 2013 WC Final
Slater at Fullback
Inglis at Centre
Hayne at Centre
Boyd on the Wing'"
I believe that both Hardaker and Tomkins have to be in the England team.
It could be achieved by having Hardaker at full back and Tomkins in the halves. Or it could be achieved by having Tomkins at full back and Hardaker in the centres. (In the latter case then you have the dilemma of choosing between Watkins and Reed).