Choosing model to answer

Hi Tutor,

I failed this exam in March 2019 with 44. During the exam while reading the case and trying to answer Q1 I noticed that both PESTEL and 5 Forces are suitable to answer the question, however neither can answer completely. I was afraid to use some part of PESTEL and some part of 5 Forces. That’s why I used PESTEL. Is it correct to mix 2 models to answer the question? Can using 2 models together harm my mark or will this make me a strong candidate?

Many thanks.