got any evidence to back that assertion up?
It flies in the face of what I have experienced in 42 years of flying.
Underthinking pilots who underprepare because they think simply learning to control the machine in a straight line makes them good pilots.
Plenty of examples after 6 years in engineering, followed by 18 years in aviation of which 7 years in training people with different backgrounds.
The thinker is always late, he is one of the most difficult people to train as his natural problem handling process is to think about it when he's supposed to act. Understanding is not a problem solution. You still die if you understand the reason why you're dying and the acting came to late. Overemphasising technical knowledge creeps into the ego of many people, and claims an idea that "they know". They usually don't, as even the most advanced theoretical pilot training is limited and does not tell full stories.
Ask any old pilot to explain the theory behind his flying, he will not be able. It doesn't matter to know the why. It matters to know how to act appropriatly.
Keep it simple saves lifes. Complicated theory wastes time.