Are you sure the engineers weren’t just petty little creatures trying to get some spotlight?
I can assure you that no engineer could win a race against either one. Additionally, Senna has proved that he do “well” with much inferior cars, there must be something going on there as well...
As someone who races every now and then for fun, I can assure you that there is skill involved and domain knowledge. A lot of domain knowledge.
You could turn that around and say that no F1 driver could design a car that would win in aero dominated F1 (mid 70s? onwards).
The car dominates in modern F1, you need look no further than the current Mercs.
Sure a good driver can outdrive the car but do you honestly think that Hamilton would've won in 2015's McLaren?
Early on, we were limited to 50 mph, and were sent out to practice racing lines around Watkins Glen. We thought we were hot stuff wheeling hard around the turns.
Then the instructor told us to get in the van and he'd drive us around giving us pointers. He drove with his left hand on the wheel, and his body turned around facing backwards at us while he lectured us. He was sliding the van around the turns at 70 mph, and I doubt his heart rate exceeded 70 BPM.
It was a very humbling experience.
He used techniques that helped the car to use the maximum possible grip, avoiding sliding or throttle partialisation
For example at Monza, in times of manual gear, he could switch from 4th to 5th in between the two turns of Lesmo, nobody else could, it meant gaining a tenth of a second every single lap and the pole position
For reference, this is how Senna throttle technique sounded at Monza's parabolica