Just a thumbs-up for CMU: their top-rated CS program requires a minor outside of CS; and they have a “BxA” program that is a specific cross-school degree combining anything (like CS) with Arts. They like cross-functional kids for sure (parent of a CS-music junior here).
They are not “almost reach” schools, they are high reach schools for anybody. Acceptance rates to Pomona are under 10%, and those to Williams are only slightly higher. As an international student, your chances are lower than that.
If you are an international student, this can count against you, since almost all colleges are need aware for international students.
All this is premature, though, since you are a sophomore in high school, and it is almost impossible to figure out chances for a students who does not yet have grades from their entire sophomore year and at least the first semester of their junior year. You have 1.5 years of the 3-3.5 years that colleges consider when they look at your application.
Also, based on your other posts, most of your ECs and achievements are still in the planning stage, and have not yet happened.
So you are really asking us to tell you what your chances of admissions are to the colleges with the lowest acceptance rates IF all of your plans succeed, and IF you maintain high grades.
You should be spending your time and energy on those ECs that you are planning and on your schoolwork to keep up those grades, not on posting here asking us what will happen IF you manage to do so. Focus on doing well in high school, not on what will happen if you do well in high school.
You are smart and hard working, don’t mess up because you are focused on what you have done and what will happen in the far future instead of focusing on what you need to do at the present.
While I am a huge proponent of Williams College, I do not think it is the absolutely best choice available for computer science. For the class of 2022, a number of students who were even considering CS as a major were unable to get into the intro course for either semester their freshman year. Demand exceeds the supply of courses.