Complex sentence: Prisoners worked more slowly than the German construction workers, even with being beat, was a source of anger and dissatisfaction to factory management, this lead to repeated request that camp authorities increase numbers of SS men to supervise prisoners and energetic capos.
Split into simpler sentences: Prisoners worked more slowly than the German construction workers, even with being beat. This was a source of anger and dissatisfaction to factory management, and lead to repeated requests that camp authorities increase the numbers of SS men to supervise prisoners and energetic capos.