By "speed-engaging" (I'm not great at creating game terms bwahahaha!) I mean that alot of players will target a mob and hit enter which activates the action bar then enter again to use an ability like Heavy stab, that will automatically take you into battle mode and engage the mob.
Basically you hit enter twice and you do whatever action you have set as No.1, instead of switching to battle mode, running to the mob and hitting it.
Its faster and more streamline and its a work around the regular slower method and it just makes you wonder, how come we cant engage a mob by clicking on it twice like every other game?
Just like how in FFXI you'll get a battle menu with all your spells, abilities, weapon skills, pet commands and ranged attack and you macro'd the abilities that you used the most, you can just set them up on the action bar which solves the thread issue, makes battles more streamline and if we ever got the level cap increased and got more abilities than the bar can hold we'll still be able to use them.
And it solves other issues like needing to open the main menu to return when you die, trade with people or use items.
I'd call myself a genius if it wasn't such an obvious solution.