The expression Sprite.Platform.VectorX returns a negative number when moving to the left, positive when moving to the right and zero when idle.
You can do the mirroring & the walk/idle animations under it, but only under the strict condition that you constrain the logic to catch the exceptions. And there are a lot exceptions.
When Sprite.Platform.VectorX is less then zero you want the mirroring to happen, but the 'walk' can not happen when in the air, and also not when there is an 'attack' playing.
The flow and the logic is not that easy. But in the end you will have to catch the 'attack' exception any way, and the 'crunch' and.......... etc.
.... and the 'is at wall' when using only the triggers to animate, you dont want it to walk when standing still for a wall.
So in the end, it will be a mix.
Using the triggers for the 'mirroring', for starting the 'jump' animation, for starting the 'fall' animation, for starting an 'attack' .... & Using the Sprite.Platform.VectorX to fall back on the 2 defaults, "walk' & idle after any of the others ended and there is not other exception in play.