With the UCs (and with other universities that admit by major), be careful how you interpret this data. It isn’t recommended to apply for one major with the intent of switching to another major, for a number of reasons.
UCs have holistic admission, and this student’s background would seem to support an interest in MechE or AeroE more clearly than it would support interest in something like EECS. So it’s not clear that a slightly higher admit rate would translate into better chances.
Switching from one engineering major to another can be complicated. At some of the UCs, it’s more difficult than at others; each has a different process. But even in the best case it would generally require one or two semesters (or 1-3 quarters), during which time a student would be required to make progress in the initial major (which might involve classes that wouldn’t be required in the new major).