Large groups of armed soldiers shooting their guns seems like a very unlikely target for a wolf attack. There was certainly a chance that soldiers alone on picket duty or patrol could have encounterd wolves, since military operations occurred in their forest habitats because the Eastern Front in WW I wasn’t static. If this story wasn’t cooked up by an Italian reporter, I would bet that a sentry seeing a wolf in the camp turned into this eleborate tale after thousands of tellings, because that is how stories go in the military. I would have to see a primary source, like an army document, a letter, or a mention in a diary or memoir, to believe to this.