Yeah, that's true.
I think the sim engines are of the same quality in both sims; the difference is in the car's physics models.
Some of them are better in AC, others in pCars.
I very much like the GT3 type cars in AC, but in pCars I prefer open-wheelers, both vintage and modern formula.

All these bullshit about simcade are coming from AC fanboys most of them they don't even have driving licence lol.
I'm 33 years old and I have some expirence in racing cars in real life, I can say both games are fine and I believe pCARS are more comprehensive as a game..