Perhaps the Protar would win in the flatness of field contest, but I don't think it's a fair comparison anyway. There's a WORLD of difference between 100 degrees of coverage and 135 degrees of coverage. To achieve a relatively flat field from, say, a 90mm lens on an 8x10 is amazing. To do it with a lens built c.1920 is nothing short of extraordinary.
(And a Protar will never beat a Goerz anything- when it comes to element separation.)