Not really sure about what you mean? I think it's fair to compare lap times as they are trying to recreate the WRX series with authentic car behavior.
Now, circuits aren't laserscanned and gravel sections can be quite different from year to year so it's not that strange that lap times aren't spot on. But when laptimes are 5-7 seconds faster on some circuits, something is still way off(imo the tire model) and should be looked at.
Last time I checked Project Cars lap times was much closer to real life on the circuits they have.
I'm still really enjoying RX in DR2 though, it's the best it's ever been!
*Seriously though Codies, why no tire management in RX?