1. What you referenced is not a study. It is a synopsis of study in popular media. It is written by someone who may, or may not know that they are doing. The author and the study he quotes misses several of the key elements of the original body of work - as he presents it.
2. If you want to get at the truth, read the original study. Then read the studies that it references to look for holes in methodology. Of course, all of this will cost several hundreds of dollar in accessing those reports.
3. Malcolm Gladwell, who popularized this theory (he is a journalist - not a scientist) based much of what he writes about on the works of Anders Ericsson. Malcolm popularized the 10,000 hour thing in main stream media, not in peer reviewed scientific journals. Because, again, Malcolm is a journalist, not a scientist. As per Dr. Ericsson, Malcolm never interviewed him, never called, him, never once spoke to him. Dr. Ericsson has publicly stated that much of what Malcolm wrote is a misrepresentation.
4. If you really want to understand what the original research entailed, look up those original papers in peer reviewed scientific journals. Pay for the subscription. Do that hard work.
5. Having trained under two national team coaches.... no doubt, morphological make-up can influence outcomes. However from my experience, and in questioning those coaches, the athletes who drill basics, over and over, until they just don't get it right, but cannot get it wrong, who can do those drills as naturally as breathing in their sleep, and have video analysis weekly, if mot daily to insure that their movements are as efficient as possible, are the ones who excel.