Guerilla campaigns were ultimately one of the most difficult types of warfare for one to emerge victorious in. That is, of course, assuming you were the one fighting against the guerillas. Hiding among the civilian population, and attacking when you were nearly forgotten, murdering in the name of your cause before retreating back to the shadows like a rat?
It was a cowardly but effective means of warfare. And unfortunately for Bruno, this was how the Red Army had chosen to fight in its last death throes. Because of this, Bruno found himself operating as a commander from afar, rather than in the field, as he preferred.
Because, frankly, there was no battlefield for him to step foot upon. The streets of Moscow, Saint Petersburg, Tsaritsyn, et cetera were the battlefields. Merely stepping out your door exposed you to unknown dangers lurking in the shadows.