I know most people do the paper in order and it's perfectly reasonable why
Both owidjaja and jazcstuart are right in terms of the practicality of doing the paper in order. I can offer an alternative if you wanted to attempt the paper differently.
I think I'm the only person who doesn't have a set order going into a paper. I read the unseen texts first, look at the questions and decide the order on the spot. I usually go with the easiest section first and hardest last so I have more time. Sometimes, the unseen texts need more time for me because I have trouble identifying techniques quickly on the spot (or they just end up being really basic ones that don't have depth behind them). At other times, I might get a really bad essay question that needs planning or creative stimuli that are more challenging for my story. I let the paper itself determine what order I do.
In the case of wasting time for the unseen, if you choose not to attempt it first, spend a few seconds just highlighting quotes you want to use for the short answers and that way, you can return to it with the reference material all there. It won't take up too much of your time and you can start on something that will make you feel more confident for the rest of the paper
Good luck for all your exams
Angelina