Ok so

/macroicon "Cleric Stance"
/ac "Cleric Stance" <me>
/hotbar change 3

and

/macroicon "Cleric Stance"
/ac "Cleric Stance" <me>
/hotbar change 1

Work exactly how I wanted, but one detail I wonder if it could be fixed; is there a way to prevent this macro from switching bars unless cleric stance is actually toggled? Like a condition for the /hotbar change # line to trigger.