Small/Big Mammal/Reptile
An interesting idea, and one for which there is "conventional" data.
If mammals were superior to Dinosaurs, we wouldn't have needed the Chixculub impactor to even the odds. Maybe mammals needed to be about dog or pig size to really work well, with our hot-blood and our fixatioj on letting the brainj have "free reign".
The Neolithic period must have been very interesting, with "crazy inventors" constantly re-di9scovering flint and chert arrow points.
It was an arms race.
Luckily "we" won...