Note that when listing the 1% example, I wrote “I realize this is an extreme and unrealistic example, but the point is cost of failure can have a big impact on important decisions.” In reality the chance of admission by major cannot be quantified by a simple differential of x%. It depends on many additional factors, including the specific student and the specific school… For example, the fields in which I found it easiest to get high grades are below, listed from easiest to hardest. I realize your list would be different, as would the OP’s, and most other persons’ in this thread.
Computer Science
Electrical Engineering (was an EE major)
Industrial Engineering
Chemistry
Humanities that especially interested me
Physics (took advanced physics sequence without having taken prerequesites)
Biology
Most Humanities GERs
Writing Intensive Humanities
Based on this list, I might have the best chance of admission as a CS major, and the worst chance as a language major. However, the Berkeley GPA list earlier suggest language might be best for admission and CS one of the worst. However, the NCES link listed higher CS GPA than the overall average, so that suggests CS is not so bad. Given the amount of variation, it’s good to have the flexibility to take some classes in different fields before making decisions that will change your life, like I stated in my original post.