1.CUHK's engineering score is very low because CUHK itself is not strong in engineering. But engineering here refers to the majors of the Institute of Technology. Communication engineering belongs to the College of Information Science and Technology, and it is one of several strong universities in CUHK, so the admission score is of course higher. General engineering belongs to the Department of Electronics, Institute of Information Science. Take an examination of communication engineering, automation, electronics and other majors, and you need 300+ before you can consider it. Moreover, CUHK's communication engineering is definitely a good major. More importantly, the IT employment environment here is good. These things are sometimes even better than the so-called rankings, not to mention the general workers of CUHK are quite strong.
This is true in theory, but CUHK seems to have drawn its own boundaries.
This can't answer you, sorry.
As a student of CUHK, I want to tell you more here. After all, many people on the Internet don't know the situation here. I am an undergraduate, so I don't have much research on the postgraduate entrance examination. I dare not say too many arbitrary words so as not to miss the landlord. I just hope I can provide some help here.