You can only really compare benchmarks done in the same area. Same principle as was being pointed out RE: the Battlefront Vega demo. We don't know where TPU does their bench run.
This is such a basic concept that it's hard to believe this is truly a technical discussion forum sometimes. We need an apples to apples benchmark before drawing any performance conclusions. The only things we can do is guesstimate based on the architecture improvements we currently know about.