I think you have the wrong mindset going into your application season. Colleges don’t have tier lists for activities (such as having, as a rule, that MUN is better than choir). The needs of the college, particularly when it comes to small LACs, often serve as the determining factor over “caliber,” as you put it, since the college is looking for a well-rounded class that contributes to all aspects of their campus. Thus, a mediocre bassoon player might get in over a highly skilled violinist, since the band needs another bassoon, rather than yet another violin. This also applies to other aspects of the applicant, such as geography (ex: a qualified candidate from Wyoming has a much better chance than an equally qualified candidate from California).
Take me, for example. I would say I have pretty strong and relatively unique EC’s and accomplishments. I applied to Amherst, Williams, and Colby, all of which had an overall 8% acceptance rate this year (although lower and perhaps varied for RD). I got waitlisted at Williams, and into Amherst and Colby (pres. scholar :)). Now, do I think that the “caliber” of my EC’s got me into those schools and waitlisted at Williams? I don’t think so. I firmly believe their decisions were based on what they needed in their class this year. Of course, levels of leadership and talent will help your admissions decision, but at the end of the day, it is the need of the college that prevails.
At the end of the day, college admissions at highly selective schools are really a crapshoot. Almost everyone who applies there is perfectly qualified and would contribute something meaningful to the institution.