An Unsurprising Surprise Attack
Some of my comics are hypothetical situations. Logical extensions of common sense applied to the game world in a comedically exaggerated fashion. Others, like this one, are only slight distorted examples of stuff my players have tried to do at my game table. Albeit without the marching band flair.
I love my group, and this is a totally valid strategy that adventurers would employ in a situation like this. But, man does it feel cheap.