what is the difference between
/cast Mortal Strike
and
/startttack
/cast Mortal Strike
Is there any reason why /startttack should NOT be added?
I believe that /startattack is equivalent to right-clicking on an enemy. If one is a hunter, doing so will use a ranged weapon (if equipped and out of melee range) xor be ready to melee when in range. If in melee range, one will start to melee. As a hunter, my targeting macro does not use /startattack. I use /petattack and give my pet a chance to engage the enemy before I start firing. When in a dungeon, my targeting macro targets whatever the tank is targeting but I also do not use /startattack to give the tank a chance get aggro. Hope this helps.
It starts your “auto attack” if you have on. Nothing more.
It’s useful for some classes and specs because there are things that’ll turn it OFF without telling you it’s been turned off.
For classes with things that set up CC that can be broken by damage it would make sense to shut off auto attack (assuming you’re in range of whatever you just CC’d) and only turn it on when you change targets or choose to break that CC.
Like most things in the game, it’s situational.