Even if 1400HP from 200Kg/h was correct, that's taking the peak figure from the time, when the cars were not really fuel limited and it made sense to design for the peak, and comparing it to the now really fuel limited and hence average-ish figure from 2014. Back then you could get more fuel in if the machanical parts could withstand it. Now the rules, not materials, impose a hard (flow) and a soft (amount) limit.
It is also comparing a figure from an engine likely made to last 10Km with the current engines forced to last for about 2000Km.
German media feeding the German rumor about the German engines at its prime.