How good are schools A and B in alternative majors that the student may choose if they switch out of chemical engineering?
Also, consider whether there is any secondary admission process or weed-out requirements for the chemical engineering major (and any alternative majors) at schools A and B.
https://nces.ed.gov/pubs2018/2018434.pdf has some information about college students changing their major. It says that 33% of bachelor’s degree students who declared their major change major within the first three years. However, this does not capture those who enter as undeclared and changed major intentions while still undeclared (or were blocked from declaring their first intended major by not passing a secondary admission process to their major).
It does say that 32% of those who initially declared engineering and engineering technology changed their majors in the first three years. Engineering majors may be somewhat more likely to be declared on entry (frosh admission to major), but that is not true at all colleges.