All five universities use the European Credit Transfer System (ECTS), meaning that all courses are measured in terms of work load for the student, including how much time you are expected to use preparing for the course. One full academic year comprises 60 ECTS credits equivalent to a total of 1500-1800 hours (one full semester equals 30 ECTS). Courses mainly come in units of 5 or 10 ECTS credits (with some exceptions).
The universities use different grading scales but all the scales can be converted to the ECTS grading scale.
Your performance at exams will be graded in accordance with the scale which is used in the institution where you are enrolled. For the master thesis you will have two supervisors, one from each of the two universities involved in the study track. You will receive one common grade for your thesis agreed upon by both institutions but according to the grading scale of the university where you conducted your thesis work.