Yet his former team is driving circles around his teams car, so still plenty to get out of these regulations for mister Fallows and his team.
There are still many differences between these 10 cars. Some more subtle, but some pretty substantial, like suspension setups and geometries or the placing of the chassis relative to the rest of the car. The RB has the tub further back than any other car for instance.
So no, I do not agree, this is (still) far form a spec series.