I think it was Raja himself that said RX Vega will be faster than the FE edition so clocks have to be as high as that card you would think to achieve this.
He never said the gaming cards would have higher clocks.speeds, only that the gaming card would have better performance for gaming. The assumption at the time was the FE cards would have professional drivers which aren't as fast for gaming.
Turns out that may not actually be true, which is very strange.
Either way, I don't see AMD releasing a single GPU rated at 375w. That is just unfathomable. There were a lot of leaked benchmarks run at nearer 1200MHz, these could absolute be engineering samples down locked and indeed that is the most likely reason for the discrepancy. However, it wouldn't surprise me one bit if the gaming cards card came in at nearer 1200MHz and 275w. Why then did Raja talk about gaming Vega being faster? Well who knows, it is AMD we are talking about "overclock dream". There could be some thing simple like the gaming cards will get 8GB of the 2.0GBPS memory and thus have more bandwidth,bit run at lower clocks.