2/ One of Sun Tzu's famous war quotes is that Speed is the essence of War. He explains that you have to exploit the enemy's unpreparedness; attack him unawares; take an unexpected route. This implies being so fast with the execution that the enemy only realizes when the harm has been done already.
However, one of my "most epic battle experiences" in the Splinterlands game is that which suppressed the advantage of speed - the Reverse speed ruleset.