Not really, no.
pCARS 2 and FM5, 6 and presumably 7 knock it into a cocked hat.
Assetto Corsa and pCARS are roughly on par, but came out 1 and 2 years ago respectively.
Given that Polyphony is almost certainly pulling the trick of counting each variation of a car as a separate model (eg. Alfa 4C (N200), 4C Gr 3., 4C Gr 4 are probably three cars) they're probably right at the bottom of the list for unique cars, and they're not high up for tracks either. I think they'll be doing well if they end up with 50 unique models, and Driveclub had that at PS4 launch.
For all that GTS may do well, it deserves no praise for it's tiny car and track list in 2017. Forza Motorsport 5 got a right bollocking for having more content nearly four years ago. For a AAA first party developer, presumably with the traditional super-size budget, the amount of content is...underwhelming?