Transitions provide the thread that makes the parts of the paper a whole, and the line that leads the reader to the writer's conclusion. Every paper should be re written. Pedagogically it is better to criticize a paper during the semester rather than at the end. Criticism of a final paper at the end of a semester has far less impact on student learning. Criticism during the semester provides an the opportunity to improve.
Writing is a slow and incremental process.
Miracles do not happen over night.