Hi, I dont think you can do that with AQA and I doubt you would have time to do two units in one year. Contact them first to find out. I would personally teach unit 3 as results (mine anyway) always seem to be much better than on Unit 2. Youll also find that when you get to Feb a lot of students seem to realise that the skills and styles of questions are repeated so tthis becomes second nature as well as the content. Aim to finish by Feb half term and revise for the rest. You wil have also more data on the students to make a decision and those who need to do short course can focus on that etc.