unfortunately with melees and the /follow command, no. but....

just walk backwards for a little while attacking. that works. or.. turn the mob around by running past it and doing a 180. your slave will be right on top of the mob usually, but he'll still attack the mob. plus side to turning the mob around, the mob cannot parry, dodge or block your slave's attack since the mob will be facing your main and not your slave.


i would also advise you to try this macro:
MAIN:
/cast [nomod, target=focustarget, harm] [nomod, harm] Death Grip
put this in a button for your main.

then...for SLAVE:
/cast [mod:alt, target=focustarget, harm] [mod:alt] Death Grip
put this in a button for your slave, but the same action key as your main.

say you put this in hotkey button #8.
press 8, your main does deathgrip.
press alt+8, your slave does death grip.
works if you switch leaders too.