try something along the lines of

/cast [target=focus-target] flame shock


I would suggest yeh go find a few targeting dummies and see if yer guys are actually targeting properly


You could also just do

/follow róflstomp
/focus róflstomp

/target focus
/cast flame shock

I'm not sure i it default behavior or if its something yeh have to change in config but what happens is it'll target the focus then automatically assist on focus-target. Which basically will makes sure it clears the dead target.