Although I dont recommend taunt for pulling bosses or anything for that matter but the reason this macro is not working is because Charge and stance both incur a GCD every time used (and so will Taunt once used).
Any ability which incurs a GCD can not be macored together in a single button click.
The correct macro would be
/castsequence [reset=target,combat] Charge, Defensive Stance, Taunt
The above macro will work by clicking 3 times, click 1 Charge, click 2 stance, click 3 Taunt.
AFAIK, Retaliation does not incur a GCD so that can be macroed into something else.
Again I haven't played much on stance dance macros for a while so my info on those maybe inaccurate.