Also Niwashi i understand what you mean but it depends what spells are worth "easily" reaching for when playing more than one class and it would be easier to keep the action bars organized for example:
PLD: action bar 1=attacks
action bar 2=attacks
action bar 3=defensive cool downs

WHM:Action bar 1=heals/ healing cool downs
action bar 2=macros
action bar 3=Defensive macros

Now it doesnt make sense to use attacking key binds from my pld for macros on my whm right?

Also ill be adding pictures in a few days for you guys to have better understanding.