Nominal tutors do not have to be in the same research group. For some reason, some tutors want to recruit students themselves, but they don't train and guide students themselves. The actual operation is to let their students or an unknown teacher train. Nominal master tutor and real tutor have different academic qualifications and experiences. When the qualifications of two tutors are different, it may happen that the actual tutor's qualifications are not as good as the nominal tutor's, so students will lack projects and educational resources. If students really want to learn something, they need to explore it slowly.