Let's say if you had a sword, sometimes you would thrust, sometimes you would slash up, or down. To add variety to the animations, as opposed to the dull and generic overhead swing.
true, but what if the animation would change depending on your movement, like if you would be jumping, you would make a downward slash, and if you were walking forward you would slash sideways, upwards, or downwards, or when you are just standing still, you would thrust.