If I was doing a paper exam with 10 questions and each student gave me the answer on a separate piece of paper, I would have much more work. I would have to find the student record, add one result before jumping to a new student record. However, if each student took 10 seconds for each question, I would start recording student answers after 10s with each question on one page rather than wait 100 seconds for the first result. When the last question is given to me, I could either have 90% of the exam already marked or have dozens of unprocessed answers on my desk.
How does the analogy hold up? The page containing questions in Moodle is displayed and the selection of multiple choice answers is handled by the student browser. The server only processes the page when the "next" button is pressed. I think breaking up one page into 10 separate question pages is going to be a lot more work for the server as it has to render and process 10 pages instead of one.
So how do you compare the two approaches? I have been using JMeter and adapting the script from https://github.com/YU-MITC/jmeter-quiz-testplan. The plan loads 1000 users and I have set up a 10 question multi-choice test, either single page or one question per page. I don't understand all the test plan but have managed to get it to run threads on the two tests. For the single page, the submission is delayed by 100 seconds with a standard deviation of 20 seconds ie 68 out of 100 will finish between 80 and 120 seconds, 95% between 60 and 140 seconds. For the single question per page, the wait time is 10 and 2 seconds per question.
I pushed it to failure with a 1000 threads each representing a different user logging in, completing the quiz and logging out. For the single page quiz, 16 had no quiz result and completion times of from under a minute to 3 min 20s. For one question per page, 148 did not complete and completion times ranged from nearly 7 to 11 minutes.
I may have completely misunderstood the way quizzes are handled and my results may reflect the JMeter setup rather than reality but I would question if breaking up a quiz pages is always a good idea.