The essay will receive word count percentage deductions because it fails to meet the 250 minimum word count by 10 words. That will have a huge effect on your preliminary score seeing as how that error will be deducted from the preliminary TA score. Next time, assure yourself of writing at least 250 words by either writing 5 lines of text or 5 sentences per paragraph.
However, I completely
It would have been more acceptable for you to indicate that you disagree with the previous statement. That way the sentence writing would have a natural flow to it and adhere to the C+C scoring considerations.
for a variety of reasons.
This does nothing to help clarify your personal opinion. It will lower your score. Next time, provide the 2 reasons that support your opinion and then indicate that you will be expanding on the reasons in the succeeding paragraphs. That will allow you to gain a higher TA score in relation to writer's opinion considerations.