Why why why?
They say it has 392kW and does only 120mph? This shows that it can only sustain ~60-80kW presumably to prevent is melting into a pool of copper & mimicking a toxic bonfire (where by mimicking I mean becoming). One must assume that the 649lb-ft is at a useless rev range too (perhaps motors stalled) or else it would piss the 0-60 of the petrol... or perhaps the petrol version has a "gearbox" which means it can stay around peak torque all the way & more torque at the wheels as slower speeds?
So pick some bigger numbers... which magically turn into a car that is slower... with not enough range to get from Oxford to Heathrow & back on 1 charge...
Meanwhile back in the real world real engineering challenges such as powering China without brown coal & supplying clean drinking water to 1bn Africans go ignored. But at least the Africans and Chinese will be able to drive in 'lectric Mercs.