[quote=@Ollumhammersong]
[@Dusty] Strictly speaking, engineering officers don't exist. The secrets needed to keep even the simplest machines operational are closely guarded secrets of the techcult that they don't give out to anyone who isn't also a priest of Mars. 
[/quote]

I mean the Death Korps of Krieg has its own engineering corp. I don't really believe the Mechanicus has a complete monopoly on tech maintenance. Imperial Guardsman are expected to maintain their own las riffles after all.