The assignment was difficult, because you had to edit a page out of context. However you did not have the background knowledge to edit an academic document that has its own jargon (like contribution to knowledge) that for you was just a vague term.
Few sentences did not carry the meaning intended, so I had to rewrite.

I edited before with TheWriteStuff, and he saw that there are things he does not know, so he sent me an e-mail to ask before editing, and it came out better.

I appreciate the knowledge of English, but for editing we need to get some content knowledge and style knowledge.

I appreciate that you wwere writing to me, so you can "grow" professionally.
Good luck!
Dr Javetz