If Zachary is near the weed smoking he will partake. Then he will go to Silva and tell him the story of Bender the Great, the robot that befriended a turtle. It was a childhood favorite of his. Shoot anything that comes close.
"I am no mere medic- I am a licensed micro-biologist and was a pioneer in my field. I'm going to show you what I can do."
Orders: I'm assuming Lt. Wolffe's feat succeeded. If not then try to kill all the zombies myself. Then, go over to a dead zombie, draw some blood and tissue samples, and engineer a vaccine against the zombie/peach virus so I am protected from them and can sell it to Lt. Wolffe and the Prussians for an exorbitant price. The great thing is that even if the feat fails and I make something horrible, I can still use it as a weapon of last resort against the scavs.
If I still have an action left then kill the nearest scav.
"Vell, dis iz not a goot plan. Huh..." Seeing the approaching zombies, the Lt gets an idea. A wonderful idea. A crezy, silly, bloody, destructive, but VUNDERFUL idea, sveethot! Hefting his halberd with the feather-hat-guy still stuck on the top, he will use feather-hat-guy as a hammer (or a ballistic missile-like-object if he has to) and try and crush the nearest opponent, be it Scav, Zombie, land mine, or dyanmite-toting-bunny-suit-thing. "Raaaaargh!"
Pvt. Hans goes beserk upon seeing an enemy with an explosive and picks up a CC weapon (preferably a katana or a battle axe; NOT one of those flimsy little fireman axes) and charges towards the bunny suit guy, killing scavs and zombies on the way.
NOTE: if the "bunny suit guy with dynamite" isn't real then remove the "run towards bunny suit guy" and go towards the fort and kill scavs and zombies.