Hi THÙY, hope that I can help and please let me know if I am wrong.
First of all, I
guess you are on the 'disagree' side, right? Or you are on 'balancing approach'?
Some people reckon that they such/thus students with problems can impact ... should put all of them in a separate group to teach.
I'm not sure but I get confused with the pronoun 'they', are 'they' referring 'some people' or 'naughty student'?
This lets other students in the class who ...
This sentence deliver: 1. student in the class, 2. student are concentrated on lesson, 3. student are being disturbed, 4. student are not understanding what their teacher taught. Sorry that I do not have sufficient skill on putting so many ideas in a single sentence but may I try to rewrite it and would be wonderful if you can help to comment it.
Others in the class may disturbed by the noise or even lead them lost their concentration to the lesson. As a result they do not learn what their teacher taught.even (even?) their study score will be declined.
All learners have Every student has equal rights ... to learn and to be taught.
..., the less (more or less?) they lose motivation to learn.
the students can this will also cost much money for more on extra facilities of for the school because they have to add more such as extra rooms, desks, chairs, and boards.,...
... needs to aware of own discipline to ...
For the concluding paragraph, I believe it would be sufficient with just paraphrasing/summarizing your body paragraphs plus closing sentence which state your position. The sentence about saying student should do good in school or class may irrelevant or inappropriate to appear there.