Earlham College 3/2 Engineering & Chemistry program

Smaller engineering focused colleges may be preferable to those who want a smaller college for engineering. But 3+2 programs seem to have a low transfer rate for whatever reasons, perhaps including financial and that the “2” school is not the small college preferred environment.

Is that more of a function of college size, or the general attitudes among the college students, faculty, and administration, as well as any applicable state laws on the subject?