the best cover

[makaz]

my defence is
god, hanley, ellis, gibbs, terlich, enright........  henderson, blee
my forwards
rocky, jjk,martin, johnson, bartel, riewoldt........ staker, oxley

my question is am i better of getting rid of henderson and bringing in  one of  scotland, obrien,hibbered or murphy and benching ellis gibbs or terlich
OR
should i swap hendo and staker and have staker as my bench cover and bring in  cloke, stokes, lewis or mayne and bench jjk.
A BIG THANX IN ADVANCE FOR THE ADVICE......