No matter how big you are having a pair of 8-10" Bowie knives driven all the way to the hilt through both your eyes will kill you instantly. Beta could certainly not remove the blades and pose with the zombies afterwards.
The survivors conveniently forget that they can use blood to mask themselves in crowds of zombies, and that the Whispers pose very little threat when confronted one on one, so they devise a poorly thought through and entirely convoluted last stand to draw the episode out longer. In reality they would have been smart enough to use this tactic to save Hilltop during the original siege.
When they finally decide to do this, they only send a small group out as a diversion, and fail to use the masking strategy with the larger group defending the hospital. It is only after the diversion fails that they decide to go with this much better plan.